Port of the C# 101 LINQ Samples rewritten into JavaScript ES 5.
Compare JavaScript (ES 5) to other LINQ examples written in:
You can run samples in your browser by opening SamplesRunner.html. Comment or uncomment the desired samples initialisation in the source code of the page. Results are in the console.
The samples below mirrors the C# LINQ samples layout with the JS immediately-invoked functions matching their corresponding C# examples.
For a side-by-side comparison, the original C# source code is displayed above the equivalent JavaScript translation.
- The Output shows the console output of running the JavaScript sample.
- Outputs ending with
...illustrates only a partial response is displayed. - The C# ObjectDumper util used is downloadable from MSDN - ObjectDumper.zip
//c#
public void Linq1()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var lowNums =
from n in numbers
where n < 5
select n;
Console.WriteLine("Numbers < 5:");
foreach (var x in lowNums)
{
Console.WriteLine(x);
}
} //JavaScript
function linq1() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var lowNums = numbers.filter(function(n) {
return n < 5;
});
console.log("Numbers < 5:");
lowNums.forEach(function(x) {
console.log(x);
});
}Numbers < 5:
4
1
3
2
0
//c#
public void Linq2()
{
List<Product> products = GetProductList();
var soldOutProducts =
from p in products
where p.UnitsInStock == 0
select p;
Console.WriteLine("Sold out products:");
foreach (var product in soldOutProducts)
{
Console.WriteLine("{0} is sold out!", product.ProductName);
}
} //JavaScript
function linq2() {
var products = getProductList();
var soldOutProducts = products.filter(function(p) {
return p.UnitsInStock === 0;
});
console.log("Sold out products:");
soldOutProducts.forEach(function(product) {
console.log(product.ProductName + " is sold out!");
});
}Sold out products:
Chef Anton's Gumbo Mix is sold out!
Alice Mutton is sold out!
Thüringer Rostbratwurst is sold out!
Gorgonzola Telino is sold out!
Perth Pasties is sold out!
//c#
public void Linq3()
{
List<Product> products = GetProductList();
var expensiveInStockProducts =
from p in products
where p.UnitsInStock > 0 && p.UnitPrice > 3.00M
select p;
Console.WriteLine("In-stock products that cost more than 3.00:");
foreach (var product in expensiveInStockProducts)
{
Console.WriteLine("{0} is in stock and costs more than 3.00.", product.ProductName);
}
} //JavaScript
function linq3() {
var products = getProductList();
var expensiveInStockProducts = products.filter(function(p) {
return p.UnitsInStock > 0 && p.UnitPrice > 3;
});
console.log("In-stock products that cost more than 3.00:");
expensiveInStockProducts.forEach(function(product) {
console.log(product.ProductName + " is in stock and costs more than 3.00.");
});
}In-stock products that cost more than 3.00:
Chai is in stock and costs more than 3.00.
Chang is in stock and costs more than 3.00.
Aniseed Syrup is in stock and costs more than 3.00.
...
//c#
public void Linq4()
{
List<Customer> customers = GetCustomerList();
var waCustomers =
from c in customers
where c.Region == "WA"
select c;
Console.WriteLine("Customers from Washington and their orders:");
foreach (var customer in waCustomers)
{
Console.WriteLine("Customer {0}: {1}", customer.CustomerID, customer.CompanyName);
foreach (var order in customer.Orders)
{
Console.WriteLine(" Order {0}: {1}", order.OrderID, order.OrderDate);
}
}
} //JavaScript
function linq4() {
var customers = getCustomerList();
var waCustomers = customers.filter(function(c) {
return c.Region === "WA";
});
console.log("Customers from Washington and their orders:");
waCustomers.forEach(function(customer) {
console.log("Customer " + customer.CustomerId + ": " + customer.CompanyName);
customer.Orders.forEach(function(order) {
console.log(" Order " + order.OrderId + ": " + order.OrderDate);
});
});
}Customers from Washington and their orders:
Customer LAZYK: Lazy K Kountry Store
Order 10482: 1997-03-21T00:00:00.000Z
Order 10545: 1997-05-22T00:00:00.000Z
Customer TRAIH: Trail's Head Gourmet Provisioners
Order 10574: 1997-06-19T00:00:00.000Z
Order 10577: 1997-06-23T00:00:00.000Z
Order 10822: 1998-01-08T00:00:00.000Z
...
//c#
public void Linq5()
{
string[] digits = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var shortDigits = digits.Where((digit, index) => digit.Length < index);
Console.WriteLine("Short digits:");
foreach (var d in shortDigits)
{
Console.WriteLine("The word {0} is shorter than its value.", d);
}
}//JavaScript
function linq5() {
var digits = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var shortDigits = digits.filter(function(digit, index) {
return digit.length < index;
});
console.log("Short digits:");
shortDigits.forEach(function(d) {
console.log("The word " + d + " is shorter than its value.");
});
}Short digits:
The word five is shorter than its value.
The word six is shorter than its value.
The word seven is shorter than its value.
The word eight is shorter than its value.
The word nine is shorter than its value.
//c#
public void Linq6()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var numsPlusOne =
from n in numbers
select n + 1;
Console.WriteLine("Numbers + 1:");
foreach (var i in numsPlusOne)
{
Console.WriteLine(i);
}
}//JavaScript
function linq6() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var numsPlusOne = numbers.map(function(n) {
return n + 1;
});
console.log("Numbers + 1:");
numsPlusOne.forEach(function(i) {
console.log(i);
});
}Numbers + 1:
6
5
2
4
10
9
7
8
3
1
//c#
public void Linq7()
{
List<Product> products = GetProductList();
var productNames =
from p in products
select p.ProductName;
Console.WriteLine("Product Names:");
foreach (var productName in productNames)
{
Console.WriteLine(productName);
}
}//JavaScript
function linq7() {
var products = getProductList();
console.log("Product Names:");
var productNames = products.map(function(p) {
return p.ProductName;
});
productNames.forEach(function(productName) {
console.log(productName);
});
}Product Names:
Chai
Chang
Aniseed Syrup
Chef Anton's Cajun Seasoning
Chef Anton's Gumbo Mix
...
//c#
public void Linq8()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
string[] strings = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var textNums =
from n in numbers
select strings[n];
Console.WriteLine("Number strings:");
foreach (var s in textNums)
{
Console.WriteLine(s);
}
}//JavaScript
function linq8() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var strings = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var textNums = numbers.map(function(n) {
return strings[n];
});
console.log("Number strings:");
textNums.forEach(function(s) {
console.log(s);
});
}Number strings:
five
four
one
three
nine
eight
six
seven
two
zero
//c#
public void Linq9()
{
string[] words = { "aPPLE", "BlUeBeRrY", "cHeRry" };
var upperLowerWords =
from w in words
select new { Upper = w.ToUpper(), Lower = w.ToLower() };
foreach (var ul in upperLowerWords)
{
Console.WriteLine("Uppercase: {0}, Lowercase: {1}", ul.Upper, ul.Lower);
}
}//JavaScript
function linq9() {
var words = ["aPPLE", "BlUeBeRrY", "cHeRry"];
var upperLowerWords = words.map(function(w) {
return {
upper: w.toUpperCase(),
lower: w.toLowerCase()
};
});
upperLowerWords.forEach(function(ul) {
console.log("Uppercase: " + ul.upper + ", Lowercase: " + ul.lower);
});
}Uppercase: APPLE, Lowercase: apple
Uppercase: BLUEBERRY, Lowercase: blueberry
Uppercase: CHERRY, Lowercase: cherry
//c#
public void Linq10()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
string[] strings = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var digitOddEvens =
from n in numbers
select new { Digit = strings[n], Even = (n % 2 == 0) };
foreach (var d in digitOddEvens)
{
Console.WriteLine("The digit {0} is {1}.", d.Digit, d.Even ? "even" : "odd");
}
}//JavaScript
function linq10() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var strings = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var digitOddEvens = numbers.map(function(n) {
return {
digit: strings[n],
even: (n % 2 === 0)
};
});
digitOddEvens.forEach(function(d) {
console.log("The digit " + d.digit + " is " + (d.even ? "even" : "odd"));
});
}The digit five is odd
The digit four is even
The digit one is odd
The digit three is odd
The digit nine is odd
The digit eight is even
The digit six is even
The digit seven is odd
The digit two is even
The digit zero is even
//c#
public void Linq11()
{
List<Product> products = GetProductList();
var productInfos =
from p in products
select new { p.ProductName, p.Category, Price = p.UnitPrice };
Console.WriteLine("Product Info:");
foreach (var productInfo in productInfos)
{
Console.WriteLine("{0} is in the category {1} and costs {2} per unit.",
productInfo.ProductName, productInfo.Category, productInfo.Price);
}
}//JavaScript
function linq11() {
var products = getProductList();
var productInfos = products.map(function(p) {
return {
productName: p.ProductName,
category: p.Category,
unitPrice: p.UnitPrice
};
});
console.log("Product Info:");
productInfos.forEach(function(productInfo) {
console.log(productInfo.productName + " is in the category " +
productInfo.category + " and costs " + productInfo.unitPrice + " per unit.");
});
}Product Info:
Chai is in the category Beverages and costs 18 per unit.
Chang is in the category Beverages and costs 19 per unit.
Aniseed Syrup is in the category Condiments and costs 10 per unit.
...
//c#
public void Linq12()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var numsInPlace = numbers.Select((num, index) => new { Num = num, InPlace = (num == index) });
Console.WriteLine("Number: In-place?");
foreach (var n in numsInPlace)
{
Console.WriteLine("{0}: {1}", n.Num, n.InPlace);
}
}//JavaScript
function linq12() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var numsInPlace = numbers.map(function(num, index) {
return {
num: num,
inPlace: (num === index)
};
});
console.log("Number: In-place?");
numsInPlace.forEach(function(n) {
console.log(n.num + ": " + n.inPlace);
});
}Number: In-place?
5: false
4: false
1: false
3: true
9: false
8: false
6: true
7: true
2: false
0: false
//c#
public void Linq13()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
string[] digits = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var lowNums =
from n in numbers
where n < 5
select digits[n];
Console.WriteLine("Numbers < 5:");
foreach (var num in lowNums)
{
Console.WriteLine(num);
}
}//JavaScript
function linq13() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var digits = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var lowNums = numbers.filter(function(n) {
return n < 5;
}).map(function(n){
return digits[n];
});
console.log("Numbers < 5:");
lowNums.forEach(function(num) {
console.log(num);
});
}Numbers < 5:
four
one
three
two
zero
//c#
public void Linq14()
{
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
var pairs =
from a in numbersA
from b in numbersB
where a < b
select new { a, b };
Console.WriteLine("Pairs where a < b:");
foreach (var pair in pairs)
{
Console.WriteLine("{0} is less than {1}", pair.a, pair.b);
}
}//JavaScript
function linq14() {
var numbersA = [0, 2, 4, 5, 6, 8, 9];
var numbersB = [1, 3, 5, 7, 8];
var pairs = numbersA.map(function(a) {
return numbersB.filter(function(b) {
return a < b;
}).map(function(b) {
return {
a: a,
b: b
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
},[]);
console.log("Pairs where a < b:");
pairs.forEach(function(pair) {
console.log(pair.a + " is less than " + pair.b);
});
}Pairs where a < b:
0 is less than 1
0 is less than 3
0 is less than 5
0 is less than 7
0 is less than 8
2 is less than 3
2 is less than 5
2 is less than 7
2 is less than 8
4 is less than 5
4 is less than 7
4 is less than 8
5 is less than 7
5 is less than 8
6 is less than 7
6 is less than 8
//c#
public void Linq15()
{
List<Customer> customers = GetCustomerList();
var orders =
from c in customers
from o in c.Orders
where o.Total < 500.00M
select new { c.CustomerID, o.OrderID, o.Total };
ObjectDumper.Write(orders);
}//JavaScript
function linq15() {
var customers = getCustomerList();
var orders = customers.map(function(customer) {
return customer.Orders.filter(function(order) {
return order.Total < 500;
}).map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId,
total: order.Total
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []);
orders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId + " Total=" + order.total);
});
}CustomerID=ALFKI OrderID=10702 Total=330.00
CustomerID=ALFKI OrderID=10952 Total=471.20
CustomerID=ANATR OrderID=10308 Total=88.80
CustomerID=ANATR OrderID=10625 Total=479.75
...
//c#
public void Linq16()
{
List<Customer> customers = GetCustomerList();
var orders =
from c in customers
from o in c.Orders
where o.OrderDate >= new DateTime(1998, 1, 1)
select new { c.CustomerID, o.OrderID, o.OrderDate };
ObjectDumper.Write(orders);
}//JavaScript
function linq16() {
var customers = getCustomerList();
var cutoffDate = new Date(1998, 0, 1);
var orders = customers.map(function(customer) {
return customer.Orders.filter(function(order) {
return (new Date(order.OrderDate)).getTime() >= cutoffDate.getTime();
}).map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId,
orderDate: order.OrderDate
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []);
orders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId +
" OrderDate=" + order.orderDate);
});
}CustomerID=ALFKI OrderID=10835 OrderDate=1998-01-15T00:00:00.000Z
CustomerID=ALFKI OrderID=10952 OrderDate=1998-03-16T00:00:00.000Z
CustomerID=ALFKI OrderID=11011 OrderDate=1998-04-09T00:00:00.000Z
CustomerID=ANATR OrderID=10926 OrderDate=1998-03-04T00:00:00.000Z
CustomerID=ANTON OrderID=10856 OrderDate=1998-01-28T00:00:00.000Z
...
//c#
public void Linq17()
{
List<Customer> customers = GetCustomerList();
var orders =
from c in customers
from o in c.Orders
where o.Total >= 2000.0M
select new { c.CustomerID, o.OrderID, o.Total };
ObjectDumper.Write(orders);
}//JavaScript
function linq17() {
var customers = getCustomerList();
var orders = customers.map(function(customer) {
return customer.Orders.filter(function(order) {
return order.Total >= 2000;
}).map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId,
total: order.Total
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []);
orders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId + " Total=" + order.total);
});
}CustomerID=ANTON OrderID=10573 Total=2082.00
CustomerID=AROUT OrderID=10558 Total=2142.90
CustomerID=AROUT OrderID=10953 Total=4441.25
CustomerID=BERGS OrderID=10384 Total=2222.40
CustomerID=BERGS OrderID=10524 Total=3192.65
...
//c#
public void Linq18()
{
List<Customer> customers = GetCustomerList();
DateTime cutoffDate = new DateTime(1997, 1, 1);
var orders =
from c in customers
where c.Region == "WA"
from o in c.Orders
where o.OrderDate >= cutoffDate
select new { c.CustomerID, o.OrderID };
ObjectDumper.Write(orders);
}//JavaScript
function linq18() {
var customers = getCustomerList();
var cutoffDate = new Date(1997, 0, 1);
var orders = customers.filter(function (customer) {
return customer.Region === "WA";
}).map(function(customer) {
return customer.Orders.filter(function(order) {
return (new Date(order.OrderDate)).getTime() >= cutoffDate.getTime();
}).map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []);
orders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId);
});
}CustomerID=LAZYK OrderID=10482
CustomerID=LAZYK OrderID=10545
CustomerID=TRAIH OrderID=10574
CustomerID=TRAIH OrderID=10577
CustomerID=TRAIH OrderID=10822
CustomerID=WHITC OrderID=10469
CustomerID=WHITC OrderID=10483
CustomerID=WHITC OrderID=10504
CustomerID=WHITC OrderID=10596
CustomerID=WHITC OrderID=10693
CustomerID=WHITC OrderID=10696
CustomerID=WHITC OrderID=10723
CustomerID=WHITC OrderID=10740
CustomerID=WHITC OrderID=10861
CustomerID=WHITC OrderID=10904
CustomerID=WHITC OrderID=11032
CustomerID=WHITC OrderID=11066
//c#
public void Linq19()
{
List<Customer> customers = GetCustomerList();
var customerOrders =
customers.SelectMany(
(cust, custIndex) =>
cust.Orders.Select(o => "Customer #" + (custIndex + 1) +
" has an order with OrderID " + o.OrderID));
ObjectDumper.Write(customerOrders);
}//JavaScript
function linq19() {
var customers = getCustomerList();
var orders = customers.map(function(customer, customerIndex) {
return customer.Orders.map(function(order) {
return "Customer #" + (customerIndex + 1) +
" has an order with OrderID " + order.OrderId;
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []);
orders.forEach(function(order) {
console.log(order);
});
}Customer #1 has an order with OrderID 10643
Customer #1 has an order with OrderID 10692
Customer #1 has an order with OrderID 10702
Customer #1 has an order with OrderID 10835
Customer #1 has an order with OrderID 10952
Customer #1 has an order with OrderID 11011
Customer #2 has an order with OrderID 10308
Customer #2 has an order with OrderID 10625
Customer #2 has an order with OrderID 10759
Customer #2 has an order with OrderID 10926
...
//c#
public void Linq20()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var first3Numbers = numbers.Take(3);
Console.WriteLine("First 3 numbers:");
foreach (var n in first3Numbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq20() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var first3Numbers = numbers.slice(0, 3);
console.log("First 3 numbers:");
first3Numbers.forEach(function(n) {
console.log(n);
});
}First 3 numbers:
5
4
1
//c#
public void Linq21()
{
List<Customer> customers = GetCustomerList();
var first3WAOrders = (
from c in customers
from o in c.Orders
where c.Region == "WA"
select new { c.CustomerID, o.OrderID, o.OrderDate })
.Take(3);
Console.WriteLine("First 3 orders in WA:");
foreach (var order in first3WAOrders)
{
ObjectDumper.Write(order);
}
}//JavaScript
function linq21() {
var customers = getCustomerList();
var first3WAOrders = customers.filter(function (customer) {
return customer.Region === "WA";
}).map(function(customer) {
return customer.Orders.map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId,
orderDate: order.OrderDate
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []).slice(0, 3);
console.log("First 3 orders in WA:");
first3WAOrders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId +
" OrderDate=" + order.orderDate);
});
}First 3 orders in WA:
CustomerID=LAZYK OrderID=10482 OrderDate=1997-03-21T00:00:00.000Z
CustomerID=LAZYK OrderID=10545 OrderDate=1997-05-22T00:00:00.000Z
CustomerID=TRAIH OrderID=10574 OrderDate=1997-06-19T00:00:00.000Z
//c#
public void Linq22()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var allButFirst4Numbers = numbers.Skip(4);
Console.WriteLine("All but first 4 numbers:");
foreach (var n in allButFirst4Numbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq22() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var allButFirst4Numbers = numbers.slice(4);
console.log("All but first 4 numbers:");
allButFirst4Numbers.forEach(function(n) {
console.log(n);
});
}All but first 4 numbers:
9
8
6
7
2
0
//c#
public void Linq23()
{
List<Customer> customers = GetCustomerList();
var waOrders =
from c in customers
from o in c.Orders
where c.Region == "WA"
select new { c.CustomerID, o.OrderID, o.OrderDate };
var allButFirst2Orders = waOrders.Skip(2);
Console.WriteLine("All but first 2 orders in WA:");
foreach (var order in allButFirst2Orders)
{
ObjectDumper.Write(order);
}
}//JavaScript
function linq23() {
var customers = getCustomerList();
var allButFirst2Orders = customers.filter(function (customer) {
return customer.Region === "WA";
}).map(function(customer) {
return customer.Orders.map(function(order) {
return {
customerId: customer.CustomerId,
orderId: order.OrderId,
orderDate: order.OrderDate
};
});
}).reduce(function(arr1, arr2) {
return arr1.concat(arr2);
}, []).slice(2);
console.log("All but first 2 orders in WA:");
allButFirst2Orders.forEach(function(order) {
console.log("CustomerID=" + order.customerId + " OrderID=" + order.orderId +
" OrderDate=" + order.orderDate);
});
}All but first 2 orders in WA:
CustomerID=TRAIH OrderID=10574 OrderDate=1997-06-19T00:00:00.000Z
CustomerID=TRAIH OrderID=10577 OrderDate=1997-06-23T00:00:00.000Z
CustomerID=TRAIH OrderID=10822 OrderDate=1998-01-08T00:00:00.000Z
CustomerID=WHITC OrderID=10269 OrderDate=1996-07-31T00:00:00.000Z
CustomerID=WHITC OrderID=10344 OrderDate=1996-11-01T00:00:00.000Z
CustomerID=WHITC OrderID=10469 OrderDate=1997-03-10T00:00:00.000Z
CustomerID=WHITC OrderID=10483 OrderDate=1997-03-24T00:00:00.000Z
CustomerID=WHITC OrderID=10504 OrderDate=1997-04-11T00:00:00.000Z
CustomerID=WHITC OrderID=10596 OrderDate=1997-07-11T00:00:00.000Z
CustomerID=WHITC OrderID=10693 OrderDate=1997-10-06T00:00:00.000Z
CustomerID=WHITC OrderID=10696 OrderDate=1997-10-08T00:00:00.000Z
CustomerID=WHITC OrderID=10723 OrderDate=1997-10-30T00:00:00.000Z
CustomerID=WHITC OrderID=10740 OrderDate=1997-11-13T00:00:00.000Z
CustomerID=WHITC OrderID=10861 OrderDate=1998-01-30T00:00:00.000Z
CustomerID=WHITC OrderID=10904 OrderDate=1998-02-24T00:00:00.000Z
CustomerID=WHITC OrderID=11032 OrderDate=1998-04-17T00:00:00.000Z
CustomerID=WHITC OrderID=11066 OrderDate=1998-05-01T00:00:00.000Z
//c#
public void Linq24()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var firstNumbersLessThan6 = numbers.TakeWhile(n => n < 6);
Console.WriteLine("First numbers less than 6:");
foreach (var n in firstNumbersLessThan6)
{
Console.WriteLine(n);
}
}//JavaScript
function linq24() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var firstNumbersLessThan6 = numbers.slice(0, (function(array, condition) {
var stopIndex = array.length;
array.some(function(n, index) {
return condition(n, index) ? false : ((stopIndex = index), true);
});
return stopIndex;
})(numbers, function(n){
return n < 6;
}));
console.log("First numbers less than 6:");
firstNumbersLessThan6.forEach(function(n) {
console.log(n);
});
}First numbers less than 6:
5
4
1
3
//c#
public void Linq25()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var firstSmallNumbers = numbers.TakeWhile((n, index) => n >= index);
Console.WriteLine("First numbers not less than their position:");
foreach (var n in firstSmallNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq25() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var firstSmallNumbers = numbers.slice(0, (function(array, condition) {
var stopIndex = array.length;
array.some(function(n, index) {
return condition(n, index) ? false : ((stopIndex = index), true);
});
return stopIndex;
})(numbers, function(n, index) {
return n >= index;
}));
console.log("First numbers not less than their position:");
firstSmallNumbers.forEach(function(n) {
console.log(n);
});
}First numbers not less than their position:
5
4
//c#
public void Linq26()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var allButFirst3Numbers = numbers.SkipWhile(n => n % 3 != 0);
Console.WriteLine("All elements starting from first element divisible by 3:");
foreach (var n in allButFirst3Numbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq26() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var allButFirst3Numbers = numbers.slice((function(array, condition) {
var stopIndex = array.length;
array.some(function(n, index) {
return condition(n, index) ? false : ((stopIndex = index), true);
});
return stopIndex;
})(numbers, function(n) {
return n % 3 != 0;
}));
console.log("All elements starting from first element divisible by 3:");
allButFirst3Numbers.forEach(function(n) {
console.log(n);
});
}All elements starting from first element divisible by 3:
3
9
8
6
7
2
0
//c#
public void Linq27()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var laterNumbers = numbers.SkipWhile((n, index) => n >= index);
Console.WriteLine("All elements starting from first element less than its position:");
foreach (var n in laterNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq27() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var laterNumbers = numbers.slice((function(array, condition) {
var stopIndex = array.length;
array.some(function(n, index) {
return condition(n, index) ? false : ((stopIndex = index), true);
});
return stopIndex;
})(numbers, function(n, index) {
return n >= index;
}));
console.log("All elements starting from first element less than its position:");
laterNumbers.forEach(function(n) {
console.log(n);
});
}All elements starting from first element less than its position:
1
3
9
8
6
7
2
0
//c#
public void Linq28()
{
string[] words = { "cherry", "apple", "blueberry" };
var sortedWords =
from w in words
orderby w
select w;
Console.WriteLine("The sorted list of words:");
foreach (var w in sortedWords)
{
Console.WriteLine(w);
}
}//JavaScript
function linq28() {
var words = ["cherry", "apple", "blueberry"];
var sortedWords = words.slice().sort();
console.log("The sorted list of words:");
sortedWords.forEach(function(w) {
console.log(w);
});
}The sorted list of words:
apple
blueberry
cherry
//c#
public void Linq29()
{
string[] words = { "cherry", "apple", "blueberry" };
var sortedWords =
from w in words
orderby w.Length
select w;
Console.WriteLine("The sorted list of words (by length):");
foreach (var w in sortedWords)
{
Console.WriteLine(w);
}
}//JavaScript
function linq29() {
var words = ["cherry", "apple", "blueberry"];
var sortedWords = words.slice().sort(function(w1, w2) {
return w1.length - w2.length;
});
console.log("The sorted list of words (by length):");
sortedWords.forEach(function(w) {
console.log(w);
});
}The sorted list of words (by length):
apple
cherry
blueberry
//c#
public void Linq30()
{
List<Product> products = GetProductList();
var sortedProducts =
from p in products
orderby p.ProductName
select p;
ObjectDumper.Write(sortedProducts);
}//JavaScript
function linq30() {
var products = getProductList();
var sortedProducts = products.slice().sort(function(p1, p2) {
if (p1.ProductName < p2.ProductName) {
return -1;
}
if (p1.ProductName > p2.ProductName) {
return 1;
}
return 0;
});
sortedProducts.forEach(function(product) {
console.log("ProductID=" + product.ProductID + " ProductName=" + product.ProductName + " Category=" +
product.Category + " UnitPrice=" + product.UnitPrice + " UnitsInStock=" + product.UnitsInStock);
});
}ProductID=17 ProductName=Alice Mutton Category=Meat/Poultry UnitPrice=39 UnitsInStock=0
ProductID=3 ProductName=Aniseed Syrup Category=Condiments UnitPrice=10 UnitsInStock=13
ProductID=40 ProductName=Boston Crab Meat Category=Seafood UnitPrice=18.4 UnitsInStock=123
ProductID=60 ProductName=Camembert Pierrot Category=Dairy Products UnitPrice=34 UnitsInStock=19
ProductID=18 ProductName=Carnarvon Tigers Category=Seafood UnitPrice=62.5 UnitsInStock=42
...
//c#
public void Linq31()
{
string[] words = { "aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry" };
var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());
ObjectDumper.Write(sortedWords);
} //JavaScript
function linq31() {
var words = ["aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry"];
var sortedWords = words.slice().sort(caseInsensitiveComparer);
sortedWords.forEach(function(w) {
console.log(w);
});
function caseInsensitiveComparer(x, y) {
if (x.toUpperCase() < y.toUpperCase()) {
return -1;
}
if (x.toUpperCase() > y.toUpperCase()) {
return 1;
}
return 0;
}
}AbAcUs
aPPLE
BlUeBeRrY
bRaNcH
cHeRry
ClOvEr
//c#
public void Linq32()
{
double[] doubles = { 1.7, 2.3, 1.9, 4.1, 2.9 };
var sortedDoubles =
from d in doubles
orderby d descending
select d;
Console.WriteLine("The doubles from highest to lowest:");
foreach (var d in sortedDoubles)
{
Console.WriteLine(d);
}
}//JavaScript
function linq32() {
var doubles = [1.7, 2.3, 1.9, 4.1, 2.9];
var sortedDoubles = doubles.slice().sort(function(a, b) {
return b - a;
});
console.log("The doubles from highest to lowest:");
sortedDoubles.forEach(function(d) {
console.log(d);
});
}The doubles from highest to lowest:
4.1
2.9
2.3
1.9
1.7
//c#
public void Linq33()
{
List<Product> products = GetProductList();
var sortedProducts =
from p in products
orderby p.UnitsInStock descending
select p;
ObjectDumper.Write(sortedProducts);
}//JavaScript
function linq33() {
var products = getProductList();
var sortedProducts = products.slice().sort(function(p1, p2) {
return p2.UnitsInStock - p1.UnitsInStock;
});
sortedProducts.forEach(function(product) {
console.log("ProductID=" + product.ProductID + " ProductName=" + product.ProductName + " Category=" +
product.Category + " UnitPrice=" + product.UnitPrice + " UnitsInStock=" + product.UnitsInStock);
});
}ProductID=75 ProductName=Rhönbräu Klosterbier Category=Beverages UnitPrice=7.75 UnitsInStock=125
ProductID=40 ProductName=Boston Crab Meat Category=Seafood UnitPrice=18.4 UnitsInStock=123
ProductID=6 ProductName=Grandma's Boysenberry Spread Category=Condiments UnitPrice=25 UnitsInStock=120
ProductID=55 ProductName=Pâté chinois Category=Meat/Poultry UnitPrice=24 UnitsInStock=115
ProductID=61 ProductName=Sirop d'érable Category=Condiments UnitPrice=28.5 UnitsInStock=113
...
//c#
public void Linq34()
{
string[] words = { "aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry" };
var sortedWords = words.OrderByDescending(a => a, new CaseInsensitiveComparer());
ObjectDumper.Write(sortedWords);
} //JavaScript
function linq34() {
var words = ["aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry"];
var sortedWords = words.slice().sort(caseInsensitiveComparer);
sortedWords.forEach(function(w) {
console.log(w);
});
function caseInsensitiveComparer(x, y) {
if (x.toUpperCase() < y.toUpperCase()) {
return 1;
}
if (x.toUpperCase() > y.toUpperCase()) {
return -1;
}
return 0;
}
}ClOvEr
cHeRry
bRaNcH
BlUeBeRrY
aPPLE
AbAcUs
//c#
public void Linq35()
{
string[] digits = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var sortedDigits =
from d in digits
orderby d.Length, d
select d;
Console.WriteLine("Sorted digits:");
foreach (var d in sortedDigits)
{
Console.WriteLine(d);
}
}//JavaScript
function linq35() {
var digits = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var sortedDigits = digits.slice().sort(function(d1, d2) {
if (d1.length > d2.length) {
return 1;
}
if (d1.length < d2.length) {
return -1;
}
if (d1 > d2) {
return 1;
}
if (d1 < d2) {
return -1
}
return 0;
});
console.log("Sorted digits:");
sortedDigits.forEach(function(d) {
console.log(d);
});
}Sorted digits:
one
six
two
five
four
nine
zero
eight
seven
three
//c#
public void Linq36()
{
string[] words = { "aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry" };
var sortedWords =
words.OrderBy(a => a.Length)
.ThenBy(a => a, new CaseInsensitiveComparer());
ObjectDumper.Write(sortedWords);
} //JavaScript
function linq36(){
var words = ["aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry"];
var sortedWords = words.slice().sort(function(a1, a2) {
if (a1.length > a2.length) {
return 1;
}
if (a1.length < a2.length) {
return -1;
}
return caseInsensitiveComparer(a1, a2);
});
sortedWords.forEach(function(w) {
console.log(w);
});
function caseInsensitiveComparer(x, y) {
if (x.toUpperCase() < y.toUpperCase()) {
return -1;
}
if (x.toUpperCase() > y.toUpperCase()) {
return 1;
}
return 0;
}
}aPPLE
AbAcUs
bRaNcH
cHeRry
ClOvEr
BlUeBeRrY
//c#
public void Linq37()
{
List<Product> products = GetProductList();
var sortedProducts =
from p in products
orderby p.Category, p.UnitPrice descending
select p;
ObjectDumper.Write(sortedProducts);
}//JavaScript
function linq37() {
var products = getProductList();
var sortedProducts = products.slice().sort(function(p1, p2) {
if (p1.Category > p2.Category) {
return 1;
}
if (p1.Category < p2.Category) {
return -1;
}
return p2.UnitPrice - p1.UnitPrice;
});
sortedProducts.forEach(function(product) {
console.log("ProductID=" + product.ProductID + " ProductName=" + product.ProductName + " Category=" +
product.Category + " UnitPrice=" + product.UnitPrice + " UnitsInStock=" + product.UnitsInStock);
});
}ProductID=38 ProductName=Côte de Blaye Category=Beverages UnitPrice=263.5 UnitsInStock=17
ProductID=43 ProductName=Ipoh Coffee Category=Beverages UnitPrice=46 UnitsInStock=17
ProductID=2 ProductName=Chang Category=Beverages UnitPrice=19 UnitsInStock=17
ProductID=39 ProductName=Chartreuse verte Category=Beverages UnitPrice=18 UnitsInStock=69
ProductID=76 ProductName=Lakkalikööri Category=Beverages UnitPrice=18 UnitsInStock=57
ProductID=1 ProductName=Chai Category=Beverages UnitPrice=18 UnitsInStock=39
ProductID=35 ProductName=Steeleye Stout Category=Beverages UnitPrice=18 UnitsInStock=20
ProductID=70 ProductName=Outback Lager Category=Beverages UnitPrice=15 UnitsInStock=15
ProductID=67 ProductName=Laughing Lumberjack Lager Category=Beverages UnitPrice=14 UnitsInStock=52
ProductID=34 ProductName=Sasquatch Ale Category=Beverages UnitPrice=14 UnitsInStock=111
...
//c#
public void Linq38()
{
string[] words = { "aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry" };
var sortedWords =
words.OrderBy(a => a.Length)
.ThenByDescending(a => a, new CaseInsensitiveComparer());
ObjectDumper.Write(sortedWords);
} //JavaScript
function linq38() {
var words = ["aPPLE", "AbAcUs", "bRaNcH", "BlUeBeRrY", "ClOvEr", "cHeRry"];
var sortedWords = words.slice().sort(function(a1, a2) {
if (a1.length > a2.length) {
return 1;
}
if (a1.length < a2.length) {
return -1;
}
return caseInsensitiveComparer(a1, a2);
});
sortedWords.forEach(function(w) {
console.log(w);
});
function caseInsensitiveComparer(x, y) {
if (x.toUpperCase() < y.toUpperCase()) {
return 1;
}
if (x.toUpperCase() > y.toUpperCase()) {
return -1;
}
return 0;
}
}aPPLE
ClOvEr
cHeRry
bRaNcH
AbAcUs
BlUeBeRrY
//c#
public void Linq39()
{
string[] digits = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
var reversedIDigits = (
from d in digits
where d[1] == 'i'
select d)
.Reverse();
Console.WriteLine("A backwards list of the digits with a second character of 'i':");
foreach (var d in reversedIDigits)
{
Console.WriteLine(d);
}
}//JavaScript
function linq39() {
var digits = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var reversedIDigits = digits.filter(function(d) {
return d[1] === "i";
}).reverse();
console.log("A backwards list of the digits with a second character of 'i':");
reversedIDigits.forEach(function(d) {
console.log(d);
});
}A backwards list of the digits with a second character of 'i':
nine
eight
six
five
//c#
public void Linq40()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var numberGroups =
from n in numbers
group n by n % 5 into g
select new { Remainder = g.Key, Numbers = g };
foreach (var g in numberGroups)
{
Console.WriteLine("Numbers with a remainder of {0} when divided by 5:", g.Remainder);
foreach (var n in g.Numbers)
{
Console.WriteLine(n);
}
}
}//JavaScript
function linq40() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var numberGroups = numbers.reduce(function(array, n) {
var key = n % 5;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(n)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [n]});
}
return array;
}, []).map(function(g, index) {
return { remainder: g.key, numbers: g.values };
});
numberGroups.forEach(function(g) {
console.log("Numbers with a remainder of " + g.remainder + " when divided by 5:");
g.numbers.forEach(function(n) {
console.log(n);
})
});
}Numbers with a remainder of 0 when divided by 5:
5
0
Numbers with a remainder of 4 when divided by 5:
4
9
Numbers with a remainder of 1 when divided by 5:
1
6
Numbers with a remainder of 3 when divided by 5:
3
8
Numbers with a remainder of 2 when divided by 5:
7
2
//c#
public void Linq41()
{
string[] words = { "blueberry", "chimpanzee", "abacus", "banana", "apple", "cheese" };
var wordGroups =
from w in words
group w by w[0] into g
select new { FirstLetter = g.Key, Words = g };
foreach (var g in wordGroups)
{
Console.WriteLine("Words that start with the letter '{0}':", g.FirstLetter);
foreach (var w in g.Words)
{
Console.WriteLine(w);
}
}
}//JavaScript
function linq41() {
var words = ["blueberry", "chimpanzee", "abacus", "banana", "apple", "cheese"];
var wordGroups = words.reduce(function(array, w) {
var key = w[0];
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(w)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [w]});
}
return array;
}, []).map(function(g, index) {
return { firstLetter : g.key, words: g.values };
});
wordGroups.forEach(function(g) {
console.log("Words that start with the letter '" + g.firstLetter + "':");
g.words.forEach(function(w) {
console.log(w);
})
});
}Words that start with the letter 'b':
blueberry
banana
Words that start with the letter 'c':
chimpanzee
cheese
Words that start with the letter 'a':
abacus
apple
//c#
public void Linq42()
{
List<Product> products = GetProductList();
var orderGroups =
from p in products
group p by p.Category into g
select new { Category = g.Key, Products = g };
ObjectDumper.Write(orderGroups, 1);
} //JavaScript
function linq42() {
var products = getProductList();
var orderGroups = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [p]});
}
return array;
}, []).map(function(g, index) {
return { category: g.key, products: g.values };
});
orderGroups.forEach(function(g) {
console.log("Category=" + g.category + " Products=...");
g.products.forEach(function(p) {
console.log("Products: ProductID=" + p.ProductID + " ProductName=" + p.ProductName +
" Category=" + p.Category + " UnitPrice=" + p.UnitPrice + " UnitsInStock=" + p.UnitsInStock);
})
});
}Category=Beverages Products=...
Products: ProductID=1 ProductName=Chai Category=Beverages UnitPrice=18 UnitsInStock=39
Products: ProductID=2 ProductName=Chang Category=Beverages UnitPrice=19 UnitsInStock=17
Products: ProductID=24 ProductName=Guaraná Fantástica Category=Beverages UnitPrice=4.5 UnitsInStock=20
Products: ProductID=34 ProductName=Sasquatch Ale Category=Beverages UnitPrice=14 UnitsInStock=111
Products: ProductID=35 ProductName=Steeleye Stout Category=Beverages UnitPrice=18 UnitsInStock=20
Products: ProductID=38 ProductName=Côte de Blaye Category=Beverages UnitPrice=263.5 UnitsInStock=17
Products: ProductID=39 ProductName=Chartreuse verte Category=Beverages UnitPrice=18 UnitsInStock=69
Products: ProductID=43 ProductName=Ipoh Coffee Category=Beverages UnitPrice=46 UnitsInStock=17
Products: ProductID=67 ProductName=Laughing Lumberjack Lager Category=Beverages UnitPrice=14 UnitsInStock=52
Products: ProductID=70 ProductName=Outback Lager Category=Beverages UnitPrice=15 UnitsInStock=15
Products: ProductID=75 ProductName=Rhönbräu Klosterbier Category=Beverages UnitPrice=7.75 UnitsInStock=125
Products: ProductID=76 ProductName=Lakkalikööri Category=Beverages UnitPrice=18 UnitsInStock=57
Category=Condiments Products=...
Products: ProductID=3 ProductName=Aniseed Syrup Category=Condiments UnitPrice=10 UnitsInStock=13
Products: ProductID=4 ProductName=Chef Anton's Cajun Seasoning Category=Condiments UnitPrice=22 UnitsInStock=53
...
//c#
public void Linq43()
{
List<Customer> customers = GetCustomerList();
var customerOrderGroups =
from c in customers
select
new
{
c.CompanyName,
YearGroups =
from o in c.Orders
group o by o.OrderDate.Year into yg
select
new
{
Year = yg.Key,
MonthGroups =
from o in yg
group o by o.OrderDate.Month into mg
select new { Month = mg.Key, Orders = mg }
}
};
ObjectDumper.Write(customerOrderGroups, 3);
} //JavaScript
function linq43() {
var customers = getCustomerList();
var customerOrderGroups = customers.map(function(c) {
return {
companyName: c.CompanyName,
yearGroups: c.Orders.reduce(function(array, o) {
var key = new Date(o.OrderDate).getFullYear();
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(o)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [o]});
}
return array;
}, []).map(function(g) {
return {
year: g.key,
monthGroups: g.values.reduce(function(array, o) {
var key = new Date(o.OrderDate).getMonth() + 1;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(o)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [o]});
}
return array;
}, []).map(function(g) {
return { month: g.key, orders: g.values };
})
};
})
};
});
customerOrderGroups.forEach(function(c) {
console.log("CompanyName=" + c.companyName + " YearGroups=...");
c.yearGroups.forEach(function(y) {
console.log("YearGroups: Year=" + y.year + " MonthGroups=...");
y.monthGroups.forEach(function(m) {
console.log("MonthGroups: Month=" + m.month + " Orders=...");
m.orders.forEach(function(o) {
console.log("Orders: OrderID=" + o.OrderId + " OrderDate=" + o.OrderDate +
" Total=" + o.Total);
});
});
});
});
}CompanyName=Alfreds Futterkiste YearGroups=...
YearGroups: Year=1997 MonthGroups=...
MonthGroups: Month=8 Orders=...
Orders: OrderID=10643 OrderDate=1997-08-25T00:00:00.000Z Total=814.50
MonthGroups: Month=10 Orders=...
Orders: OrderID=10692 OrderDate=1997-10-03T00:00:00.000Z Total=878.00
Orders: OrderID=10702 OrderDate=1997-10-13T00:00:00.000Z Total=330.00
YearGroups: Year=1998 MonthGroups=...
MonthGroups: Month=1 Orders=...
Orders: OrderID=10835 OrderDate=1998-01-15T00:00:00.000Z Total=845.80
MonthGroups: Month=3 Orders=...
Orders: OrderID=10952 OrderDate=1998-03-16T00:00:00.000Z Total=471.20
MonthGroups: Month=4 Orders=...
Orders: OrderID=11011 OrderDate=1998-04-09T00:00:00.000Z Total=933.50
...
//c#
public void Linq44()
{
string[] anagrams = { "from ", " salt", " earn ", " last ", " near ", " form " };
var orderGroups = anagrams.GroupBy(w => w.Trim(), new AnagramEqualityComparer());
ObjectDumper.Write(orderGroups, 1);
} //JavaScript
function linq44() {
var anagrams = ["from ", " salt", " earn ", " last ", " near ", " form "];
var anagramGroups = anagrams.reduce(function(array, w) {
var key = w.replace(/^\s+|\s+$/g, "");
var hasKey = array.some(function(item) {
return anagramEqualityComparer(item.key, key) ? ((item.values.push(w)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [w]});
}
return array;
}, []).map(function(g) {
return { word: g.key, anagrams: g.values };
});
anagramGroups.forEach(function(g) {
console.log("...");
g.anagrams.forEach(function(a) {
console.log("'" + a + "'");
});
});
function anagramEqualityComparer(x, y) {
return getCanonicalString(x) === getCanonicalString(y);
function getCanonicalString(word) {
var wordChars = word.split("");
wordChars.sort();
return wordChars.join("");
}
}
}...
'from '
' form '
...
' salt'
' last '
...
' earn '
' near '
//c#
public void Linq45()
{
string[] anagrams = { "from ", " salt", " earn ", " last ", " near ", " form " };
var orderGroups = anagrams.GroupBy(
w => w.Trim(),
a => a.ToUpper(),
new AnagramEqualityComparer()
);
ObjectDumper.Write(orderGroups, 1);
} //JavaScript
function linq45() {
var anagrams = ["from ", " salt", " earn ", " last ", " near ", " form "];
var anagramGroups = anagrams.reduce(function(array, w) {
var key = w.replace(/^\s+|\s+$/g, "");
var hasKey = array.some(function(item) {
return anagramEqualityComparer(item.key, key) ? ((item.values.push(w)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [w]});
}
return array;
}, []).map(function(g) {
return { word: g.key, anagrams: g.values };
}).map(function(g) {
return {
word: g.word.toUpperCase(),
anagrams: g.anagrams.map(function(a) {
return a.toUpperCase();
})
};
});
anagramGroups.forEach(function(g) {
console.log("...");
g.anagrams.forEach(function(a) {
console.log("'" + a + "'");
});
});
function anagramEqualityComparer(x, y) {
return getCanonicalString(x) === getCanonicalString(y);
function getCanonicalString(word) {
var wordChars = word.split("");
wordChars.sort();
return wordChars.join("");
}
}
}...
'FROM '
' FORM '
...
' SALT'
' LAST '
...
' EARN '
' NEAR '
//c#
public void Linq46()
{
int[] factorsOf300 = { 2, 2, 3, 5, 5 };
var uniqueFactors = factorsOf300.Distinct();
Console.WriteLine("Prime factors of 300:");
foreach (var f in uniqueFactors)
{
Console.WriteLine(f);
}
}//JavaScript
function linq46() {
var factorsOf300 = [2, 2, 3, 5, 5];
var uniqueFactors = factorsOf300.filter(function(f, index, array) {
return array.indexOf(f) === index;
});
console.log("Prime factors of 300:");
uniqueFactors.forEach(function(f) {
console.log(f);
});
}Prime factors of 300:
2
3
5
//c#
public void Linq47()
{
List<Product> products = GetProductList();
var categoryNames = (
from p in products
select p.Category)
.Distinct();
Console.WriteLine("Category names:");
foreach (var n in categoryNames)
{
Console.WriteLine(n);
}
}//JavaScript
function linq47() {
var products = getProductList();
var categoryNames = products.map(function(p) {
return p.Category;
}).filter(function(p, index, array) {
return array.indexOf(p) === index;
});
console.log("Category names:");
categoryNames.forEach(function(n) {
console.log(n);
});
}Category names:
Beverages
Condiments
Produce
Meat/Poultry
Seafood
Dairy Products
Confections
Grains/Cereals
//c#
public void Linq48()
{
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
var uniqueNumbers = numbersA.Union(numbersB);
Console.WriteLine("Unique numbers from both arrays:");
foreach (var n in uniqueNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq48() {
var numbersA = [0, 2, 4, 5, 6, 8, 9];
var numbersB = [1, 3, 5, 7, 8];
var uniqueNumbers = numbersA.concat(numbersB)
.filter(function(n, index, array) {
return array.indexOf(n) === index;
});
console.log("Unique numbers from both arrays:");
uniqueNumbers.forEach(function(n) {
console.log(n);
});
}Unique numbers from both arrays:
0
2
4
5
6
8
9
1
3
7
//c#
public void Linq49()
{
List<Product> products = GetProductList();
List<Customer> customers = GetCustomerList();
var productFirstChars =
from p in products
select p.ProductName[0];
var customerFirstChars =
from c in customers
select c.CompanyName[0];
var uniqueFirstChars = productFirstChars.Union(customerFirstChars);
Console.WriteLine("Unique first letters from Product names and Customer names:");
foreach (var ch in uniqueFirstChars)
{
Console.WriteLine(ch);
}
}//JavaScript
function linq49() {
var products = getProductList();
var customers = getCustomerList();
var productFirstChars = products.map(function(p) {
return p.ProductName[0];
});
var customerFirstChars = customers.map(function(c) {
return c.CompanyName[0];
});
var uniqueFirstChars = productFirstChars.concat(customerFirstChars)
.filter(function(ch, index, array) {
return array.indexOf(ch) === index;
});
console.log("Unique first letters from Product names and Customer names:");
uniqueFirstChars.forEach(function(ch) {
console.log(ch);
});
}Unique first letters from Product names and Customer names:
C
A
G
U
N
M
I
Q
K
T
P
S
R
B
J
Z
V
F
E
W
L
O
D
H
//c#
public void Linq50()
{
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
var commonNumbers = numbersA.Intersect(numbersB);
Console.WriteLine("Common numbers shared by both arrays:");
foreach (var n in commonNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq50() {
var numbersA = [0, 2, 4, 5, 6, 8, 9];
var numbersB = [1, 3, 5, 7, 8];
var commonNumbers = numbersA.filter(function(n) {
return numbersB.indexOf(n) !== -1;
}).filter(function(n, index, array) {
return array.indexOf(n) === index;
});
console.log("Common numbers shared by both arrays:");
commonNumbers.forEach(function(n) {
console.log(n);
});
}Common numbers shared by both arrays:
5
8
//c#
public void Linq51()
{
List<Product> products = GetProductList();
List<Customer> customers = GetCustomerList();
var productFirstChars =
from p in products
select p.ProductName[0];
var customerFirstChars =
from c in customers
select c.CompanyName[0];
var commonFirstChars = productFirstChars.Intersect(customerFirstChars);
Console.WriteLine("Common first letters from Product names and Customer names:");
foreach (var ch in commonFirstChars)
{
Console.WriteLine(ch);
}
}//JavaScript
function linq51() {
var products = getProductList();
var customers = getCustomerList();
var productFirstChars = products.map(function(p) {
return p.ProductName[0];
});
var customerFirstChars = customers.map(function(c) {
return c.CompanyName[0];
});
var commonFirstChars = productFirstChars.filter(function(ch) {
return customerFirstChars.indexOf(ch) !== -1;
})
.filter(function(ch, index, array) {
return array.indexOf(ch) === index;
});
console.log("Common first letters from Product names and Customer names:");
commonFirstChars.forEach(function(ch) {
console.log(ch);
});
}Common first letters from Product names and Customer names:
C
A
G
N
M
I
Q
K
T
P
S
R
B
V
F
E
W
L
O
//c#
public void Linq52()
{
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
IEnumerable<int> aOnlyNumbers = numbersA.Except(numbersB);
Console.WriteLine("Numbers in first array but not second array:");
foreach (var n in aOnlyNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq52() {
var numbersA = [0, 2, 4, 5, 6, 8, 9];
var numbersB = [1, 3, 5, 7, 8];
var aOnlyNumbers = numbersA.filter(function(n) {
return numbersB.indexOf(n) === -1;
}).filter(function(n, index, array) {
return array.indexOf(n) === index;
});
console.log("Numbers in first array but not second array:");
aOnlyNumbers.forEach(function(n) {
console.log(n);
});
}Numbers in first array but not second array:
0
2
4
6
9
//c#
public void Linq53()
{
List<Product> products = GetProductList();
List<Customer> customers = GetCustomerList();
var productFirstChars =
from p in products
select p.ProductName[0];
var customerFirstChars =
from c in customers
select c.CompanyName[0];
var productOnlyFirstChars = productFirstChars.Except(customerFirstChars);
Console.WriteLine("First letters from Product names, but not from Customer names:");
foreach (var ch in productOnlyFirstChars)
{
Console.WriteLine(ch);
}
}//JavaScript
function linq53() {
var products = getProductList();
var customers = getCustomerList();
var productFirstChars = products.map(function(p) {
return p.ProductName[0];
});
var customerFirstChars = customers.map(function(c) {
return c.CompanyName[0];
});
var productOnlyFirstChars = productFirstChars.filter(function(ch) {
return customerFirstChars.indexOf(ch) === -1;
})
.filter(function(ch, index, array) {
return array.indexOf(ch) === index;
});
console.log("First letters from Product names, but not from Customer names:");
productOnlyFirstChars.forEach(function(ch) {
console.log(ch);
});
}First letters from Product names, but not from Customer names:
U
J
Z
//c#
public void Linq54()
{
double[] doubles = { 1.7, 2.3, 1.9, 4.1, 2.9 };
var sortedDoubles =
from d in doubles
orderby d descending
select d;
var doublesArray = sortedDoubles.ToArray();
Console.WriteLine("Every other double from highest to lowest:");
for (int d = 0; d < doublesArray.Length; d += 2)
{
Console.WriteLine(doublesArray[d]);
}
}//JavaScript
function linq54() {
var doubles = [1.7, 2.3, 1.9, 4.1, 2.9];
var sortedDoubles = doubles.slice().sort(function(d1, d2) {
if (d1 > d2) {
return -1;
}
if (d1 < d2) {
return 1;
}
return d1 - d2;
});
var doublesArray = Array.prototype.slice.call(sortedDoubles);
console.log("Every other double from highest to lowest:");
for (var d = 0, length = doublesArray.length; d < length; d += 2)
{
console.log(doublesArray[d]);
}
}Every other double from highest to lowest:
4.1
2.3
1.7
//c#
public void Linq55()
{
string[] words = { "cherry", "apple", "blueberry" };
var sortedWords =
from w in words
orderby w
select w;
var wordList = sortedWords.ToList();
Console.WriteLine("The sorted word list:");
foreach (var w in wordList)
{
Console.WriteLine(w);
}
}//JavaScript
function linq55() {
var words = ["cherry", "apple", "blueberry"];
var sortedWords = words.slice().sort();
var wordList = Array.prototype.slice.call(sortedWords);
console.log("The sorted word list:");
wordList.forEach(function(w) {
console.log(w);
});
}The sorted word list:
apple
blueberry
cherry
//c#
public void Linq56()
{
var scoreRecords = new[] { new {Name = "Alice", Score = 50},
new {Name = "Bob" , Score = 40},
new {Name = "Cathy", Score = 45}
};
var scoreRecordsDict = scoreRecords.ToDictionary(sr => sr.Name);
Console.WriteLine("Bob's score: {0}", scoreRecordsDict["Bob"]);
}//JavaScript
function linq56() {
var scoreRecords = [
{ name: "Alice", score: 50 },
{ name: "Bob" , score: 40 },
{ name: "Cathy", score: 45 }
];
var scoreRecordsDict = scoreRecords.reduce(function(resultObj, sr) {
var key = sr.name;
resultObj[key] = sr;
return resultObj;
}, {});
console.log("Bob's score: { name: " + scoreRecordsDict["Bob"].name +
", score: " + scoreRecordsDict["Bob"].score + " }");
}Bob's score: { name: Bob, score: 40 }
//c#
public void Linq57()
{
object[] numbers = { null, 1.0, "two", 3, "four", 5, "six", 7.0 };
var doubles = numbers.OfType<double>();
Console.WriteLine("Numbers stored as doubles:");
foreach (var d in doubles)
{
Console.WriteLine(d);
}
}//JavaScript
function linq57() {
var numbers = [null, 1.0, "two", 3, "four", 5, "six", 7.0];
var doubles = numbers.filter(function(n) {
return n === Number(n) && n % 1 !== 0;
});
console.log("Numbers stored as doubles:");
doubles.forEach(function (d) {
console.log(d);
});
}Numbers stored as doubles:
In JavaScript types of number 1 and number 1.0 are the same and equal integer, so 1 == 1.0 as well as 1 === 1.0. As a result, in the numbers array there are no any number that might be considered as double.
//c#
public void Linq58()
{
List<Product> products = GetProductList();
Product product12 = (
from p in products
where p.ProductID == 12
select p)
.First();
ObjectDumper.Write(product12);
}//JavaScript
function linq58() {
var products = getProductList();
var product12 = products.filter(function(p) {
return p.ProductID === 12;
})[0];
console.log("ProductID=" + product12.ProductID + " ProductName=" + product12.ProductName +
" Category=" + product12.Category + " UnitPrice=" + product12.UnitPrice +
" UnitsInStock=" + product12.UnitsInStock);
}ProductID=12 ProductName=Queso Manchego La Pastora Category=Dairy Products UnitPrice=38 UnitsInStock=86
//c#
public void Linq59()
{
string[] strings = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
string startsWithO = strings.First(s => s[0] == 'o');
Console.WriteLine("A string starting with 'o': {0}", startsWithO);
}//JavaScript
function linq59() {
var strings = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var startsWithO = strings.filter(function(s) {
return s[0] === "o";
})[0];
console.log("A string starting with 'o': " + startsWithO);
}A string starting with 'o': one
//c#
public void Linq61()
{
int[] numbers = { };
int firstNumOrDefault = numbers.FirstOrDefault();
Console.WriteLine(firstNumOrDefault);
}//JavaScript
function linq61() {
var numbers = [];
var intDefaultValue = 0;
var firstNumOrDefault = numbers[0] || intDefaultValue;
console.log(firstNumOrDefault);
}0
JavaScript returns undefined as default value for all types. Because of this you should specify some default value (in this case, intDefaultValue).
//c#
public void Linq62()
{
List<Product> products = GetProductList();
Product product789 = products.FirstOrDefault(p => p.ProductID == 789);
Console.WriteLine("Product 789 exists: {0}", product789 != null);
}//JavaScript
function linq62() {
var products = getProductList();
var defaultProductValue = {};
var product789 = products.filter(function(p) {
return p.ProductID === 789;
})[0] || defaultProductValue;
console.log("Product 789 exists: " + !product789);
}Product 789 exists: false
JavaScript returns undefined as default value for all types. Because of this you should specify some default value (in this case, defaultProductValue).
//c#
public void Linq64()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int fourthLowNum = (
from n in numbers
where n > 5
select n)
.ElementAt(1); // second number is index 1 because sequences use 0-based indexing
Console.WriteLine("Second number > 5: {0}", fourthLowNum);
}//JavaScript
function linq64() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var fourthLowNum = numbers.filter(function(n) {
return n > 5;
})[1];
console.log("Second number > 5: " + fourthLowNum);
}Second number > 5: 8
//c#
public void Linq65()
{
var numbers =
from n in Enumerable.Range(100, 50)
select new { Number = n, OddEven = n % 2 == 1 ? "odd" : "even" };
foreach (var n in numbers)
{
Console.WriteLine("The number {0} is {1}.", n.Number, n.OddEven);
}
}//JavaScript
function linq65() {
var numbers = Array.apply(null, Array(50))
.map(function(element, index) {
return index + 100;
}).map(function(n) {
return {
number: n,
oddEven: n % 2 === 1 ? "odd" : "even"
};
});
numbers.forEach(function(n) {
console.log("The number " + n.number + " is " + n.oddEven + ".");
});
}The number 100 is even.
The number 101 is odd.
The number 102 is even.
The number 103 is odd.
The number 104 is even.
The number 105 is odd.
The number 106 is even.
The number 107 is odd.
The number 108 is even.
The number 109 is odd.
The number 110 is even.
...
//c#
public void Linq66()
{
var numbers = Enumerable.Repeat(7, 10);
foreach (var n in numbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq66() {
var numbers = Array.apply(null, Array(10))
.map(function() {
return 7;
});
numbers.forEach(function(n) {
console.log(n);
});
}7
7
7
7
7
7
7
7
7
7
//c#
public void Linq67()
{
string[] words = { "believe", "relief", "receipt", "field" };
bool iAfterE = words.Any(w => w.Contains("ei"));
Console.WriteLine("There is a word that contains in the list that contains 'ei': {0}", iAfterE);
}//JavaScript
function linq67() {
var words = ["believe", "relief", "receipt", "field"];
var iAfterE = words.some(function(w) {
return w.indexOf("ei") > -1;
});
console.log("There is a word that contains in the list that contains 'ei': " + iAfterE);
}There is a word that contains in the list that contains 'ei': true
//c#
public void Linq69()
{
List<Product> products = GetProductList();
var productGroups =
from p in products
group p by p.Category into g
where g.Any(p => p.UnitsInStock == 0)
select new { Category = g.Key, Products = g };
ObjectDumper.Write(productGroups, 1);
}//JavaScript
function linq69() {
var products = getProductList();
var productGroups = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey) {
array.push({ key: key, values: [p] });
}
return array;
}, []).filter(function(g) {
return g.values.some(function(p) {
return p.UnitsInStock === 0;
});
}).map(function(g, index) {
return { category: g.key, products: g.values };
});
productGroups.forEach(function(g) {
console.log("Category=" + g.category + " Products=...");
g.products.forEach(function(p) {
console.log("Products: ProductID=" + p.ProductID + " ProductName=" + p.ProductName +
" Category=" + p.Category + " UnitPrice=" + p.UnitPrice + " UnitsInStock=" + p.UnitsInStock);
})
});
}Category=Condiments Products=...
Products: ProductID=3 ProductName=Aniseed Syrup Category=Condiments UnitPrice=10 UnitsInStock=13
Products: ProductID=4 ProductName=Chef Anton's Cajun Seasoning Category=Condiments UnitPrice=22 UnitsInStock=53
Products: ProductID=5 ProductName=Chef Anton's Gumbo Mix Category=Condiments UnitPrice=21.35 UnitsInStock=0
Products: ProductID=6 ProductName=Grandma's Boysenberry Spread Category=Condiments UnitPrice=25 UnitsInStock=120
Products: ProductID=8 ProductName=Northwoods Cranberry Sauce Category=Condiments UnitPrice=40 UnitsInStock=6
Products: ProductID=15 ProductName=Genen Shouyu Category=Condiments UnitPrice=15.5 UnitsInStock=39
Products: ProductID=44 ProductName=Gula Malacca Category=Condiments UnitPrice=19.45 UnitsInStock=27
Products: ProductID=61 ProductName=Sirop d'érable Category=Condiments UnitPrice=28.5 UnitsInStock=113
Products: ProductID=63 ProductName=Vegie-spread Category=Condiments UnitPrice=43.9 UnitsInStock=24
Products: ProductID=65 ProductName=Louisiana Fiery Hot Pepper Sauce Category=Condiments UnitPrice=21.05
UnitsInStock=76
Products: ProductID=66 ProductName=Louisiana Hot Spiced Okra Category=Condiments UnitPrice=17 UnitsInStock=4
Products: ProductID=77 ProductName=Original Frankfurter grüne Soße Category=Condiments UnitPrice=13 UnitsInStock=32
Category=Meat/Poultry Products=...
...
//c#
public void Linq70()
{
int[] numbers = { 1, 11, 3, 19, 41, 65, 19 };
bool onlyOdd = numbers.All(n => n % 2 == 1);
Console.WriteLine("The list contains only odd numbers: {0}", onlyOdd);
}//JavaScript
function linq70() {
var numbers = [1, 11, 3, 19, 41, 65, 19];
var onlyOdd = numbers.every(function(n) {
return n % 2 === 1;
});
console.log("The list contains only odd numbers: " + onlyOdd);
}The list contains only odd numbers: true
//c#
public void Linq72()
{
List<Product> products = GetProductList();
var productGroups =
from p in products
group p by p.Category into g
where g.All(p => p.UnitsInStock > 0)
select new { Category = g.Key, Products = g };
ObjectDumper.Write(productGroups, 1);
}//JavaScript
function linq72() {
var products = getProductList();
var productGroups = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey) {
array.push({ key: key, values: [p] });
}
return array;
}, []).filter(function(g) {
return g.values.every(function(p) {
return p.UnitsInStock > 0;
});
}).map(function(g, index) {
return { category: g.key, products: g.values };
});
productGroups.forEach(function(g) {
console.log("Category=" + g.category + " Products=...");
g.products.forEach(function(p) {
console.log("Products: ProductID=" + p.ProductID + " ProductName=" + p.ProductName +
" Category=" + p.Category + " UnitPrice=" + p.UnitPrice + " UnitsInStock=" + p.UnitsInStock);
})
});
}Category=Beverages Products=...
Products: ProductID=1 ProductName=Chai Category=Beverages UnitPrice=18 UnitsInStock=39
Products: ProductID=2 ProductName=Chang Category=Beverages UnitPrice=19 UnitsInStock=17
Products: ProductID=24 ProductName=Guaraná Fantástica Category=Beverages UnitPrice=4.5 UnitsInStock=20
Products: ProductID=34 ProductName=Sasquatch Ale Category=Beverages UnitPrice=14 UnitsInStock=111
Products: ProductID=35 ProductName=Steeleye Stout Category=Beverages UnitPrice=18 UnitsInStock=20
Products: ProductID=38 ProductName=Côte de Blaye Category=Beverages UnitPrice=263.5 UnitsInStock=17
Products: ProductID=39 ProductName=Chartreuse verte Category=Beverages UnitPrice=18 UnitsInStock=69
Products: ProductID=43 ProductName=Ipoh Coffee Category=Beverages UnitPrice=46 UnitsInStock=17
Products: ProductID=67 ProductName=Laughing Lumberjack Lager Category=Beverages UnitPrice=14 UnitsInStock=52
Products: ProductID=70 ProductName=Outback Lager Category=Beverages UnitPrice=15 UnitsInStock=15
Products: ProductID=75 ProductName=Rhönbräu Klosterbier Category=Beverages UnitPrice=7.75 UnitsInStock=125
Products: ProductID=76 ProductName=Lakkalikööri Category=Beverages UnitPrice=18 UnitsInStock=57
Category=Produce Products=...
...
//c#
public void Linq73()
{
int[] factorsOf300 = { 2, 2, 3, 5, 5 };
int uniqueFactors = factorsOf300.Distinct().Count();
Console.WriteLine("There are {0} unique factors of 300.", uniqueFactors);
}//JavaScript
function linq73() {
var factorsOf300 = [2, 2, 3, 5, 5];
var uniqueFactors = factorsOf300.filter(function(f, index, array) {
return array.indexOf(f) === index;
}).length;
console.log("There are " + uniqueFactors + " unique factors of 300.");
}There are 3 unique factors of 300.
//c#
public void Linq74()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int oddNumbers = numbers.Count(n => n % 2 == 1);
Console.WriteLine("There are {0} odd numbers in the list.", oddNumbers);
}//JavaScript
function linq74() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var oddNumbers = numbers.filter(function(n) {
return n % 2 === 1;
}).length;
console.log("There are " + oddNumbers + " odd numbers in the list.");
}There are 5 odd numbers in the list.
//c#
public void Linq76()
{
List<Customer> customers = GetCustomerList();
var orderCounts =
from c in customers
select new { c.CustomerID, OrderCount = c.Orders.Count() };
ObjectDumper.Write(orderCounts);
}//JavaScript
function linq76() {
var customers = getCustomerList();
var orderCounts = customers.map(function(c) {
return {
customerId: c.CustomerId,
orderCount: c.Orders.length
};
});
orderCounts.forEach(function(c) {
console.log("CustomerID=" + c.customerId + " OrderCount=" + c.orderCount);
});
}CustomerID=ALFKI OrderCount=6
CustomerID=ANATR OrderCount=4
CustomerID=ANTON OrderCount=7
CustomerID=AROUT OrderCount=13
CustomerID=BERGS OrderCount=18
CustomerID=BLAUS OrderCount=7
CustomerID=BLONP OrderCount=11
...
//c#
public void Linq77()
{
List<Product> products = GetProductList();
var categoryCounts =
from p in products
group p by p.Category into g
select new { Category = g.Key, ProductCount = g.Count() };
ObjectDumper.Write(categoryCounts
}//JavaScript
function linq77() {
var products = getProductList();
var categoryCounts = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({key: key, values: [p]});
}
return array;
}, []).map(function(g, index) {
return { category: g.key, productCount: g.values.length };
});
categoryCounts.forEach(function(p) {
console.log("Category=" + p.category + " ProductCount=" + p.productCount);
});
}Category=Beverages ProductCount=12
Category=Condiments ProductCount=12
Category=Produce ProductCount=5
Category=Meat/Poultry ProductCount=6
Category=Seafood ProductCount=12
Category=Dairy Products ProductCount=10
Category=Confections ProductCount=13
Category=Grains/Cereals ProductCount=7
//c#
public void Linq78()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
double numSum = numbers.Sum();
Console.WriteLine("The sum of the numbers is {0}.", numSum);
}//JavaScript
function linq78() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var numSum = numbers.reduce(function(sum, number) {
return sum + number;
}, 0);
console.log("The sum of the numbers is " + numSum + ".");
}The sum of the numbers is 45.
//c#
public void Linq79()
{
string[] words = { "cherry", "apple", "blueberry" };
double totalChars = words.Sum(w => w.Length);
Console.WriteLine("There are a total of {0} characters in these words.", totalChars);
}//JavaScript
function linq79() {
var words = ["cherry", "apple", "blueberry"];
var totalChars = words.reduce(function(sum, word) {
return sum + word.length;
}, 0);
console.log("There are a total of " + totalChars + " characters in these words.");
}There are a total of 20 characters in these words.
//c#
public void Linq80()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
select new { Category = g.Key, TotalUnitsInStock = g.Sum(p => p.UnitsInStock) };
ObjectDumper.Write(categories);
}//JavaScript
function linq80() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g, index) {
return {
category: g.key,
totalUnitsInStock: g.values.reduce(function(sum, product) {
return sum + product.UnitsInStock;
}, 0)
};
});
categories.forEach(function(p) {
console.log("Category=" + p.category + " TotalUnitsInStock=" + p.totalUnitsInStock);
});
}Category=Beverages TotalUnitsInStock=559
Category=Condiments TotalUnitsInStock=507
Category=Produce TotalUnitsInStock=100
Category=Meat/Poultry TotalUnitsInStock=165
Category=Seafood TotalUnitsInStock=701
Category=Dairy Products TotalUnitsInStock=393
Category=Confections TotalUnitsInStock=386
Category=Grains/Cereals TotalUnitsInStock=308
//c#
public void Linq81()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int minNum = numbers.Min();
Console.WriteLine("The minimum number is {0}.", minNum);
}//JavaScript
function linq81() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var minNum = Math.min.apply(Math, numbers);
console.log("The minimum number is " + minNum + ".");
}The minimum number is 0.
//c#
public void Linq82()
{
string[] words = { "cherry", "apple", "blueberry" };
int shortestWord = words.Min(w => w.Length);
Console.WriteLine("The shortest word is {0} characters long.", shortestWord);
}//JavaScript
function linq82() {
var words = ["cherry", "apple", "blueberry"];
var shortestWord = Math.min.apply(Math, words.map(function(w) {
return w.length;
}));
console.log("The shortest word is " + shortestWord + " characters long.");
}The shortest word is 5 characters long.
//c#
public void Linq83()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
select new { Category = g.Key, CheapestPrice = g.Min(p => p.UnitPrice) };
ObjectDumper.Write(categories);
}//JavaScript
function linq83() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g) {
return {
category: g.key,
cheapestPrice: Math.min.apply(Math, g.values.map(function(p) {
return p.UnitPrice;
}))
};
});
categories.forEach(function(p) {
console.log("Category=" + p.category + " CheapestPrice=" + p.cheapestPrice);
});
}Category=Beverages CheapestPrice=4.5
Category=Condiments CheapestPrice=10
Category=Produce CheapestPrice=10
Category=Meat/Poultry CheapestPrice=7.45
Category=Seafood CheapestPrice=6
Category=Dairy Products CheapestPrice=2.5
Category=Confections CheapestPrice=9.2
Category=Grains/Cereals CheapestPrice=7
//c#
public void Linq84()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
let minPrice = g.Min(p => p.UnitPrice)
select new { Category = g.Key, CheapestProducts = g.Where(p => p.UnitPrice == minPrice) };
ObjectDumper.Write(categories, 1);
}//JavaScript
function linq84() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g) {
var minPrice = Math.min.apply(Math, g.values.map(function(p) {
return p.UnitPrice;
}));
return {
category: g.key,
cheapestProducts: g.values.filter(function(p) {
return p.UnitPrice === minPrice;
})
};
});
categories.forEach(function(g) {
console.log("Category=" + g.category + " CheapestProducts=...");
g.cheapestProducts.forEach(function(p) {
console.log("CheapestProducts: ProductID=" + p.ProductID + " ProductName=" + p.ProductName +
" Category=" + p.Category + " UnitPrice=" + p.UnitPrice + " UnitsInStock=" + p.UnitsInStock);
});
});
}Category=Beverages CheapestProducts=...
CheapestProducts: ProductID=24 ProductName=Guaraná Fantástica Category=Beverages UnitPrice=4.5 UnitsInStock=20
Category=Condiments CheapestProducts=...
CheapestProducts: ProductID=3 ProductName=Aniseed Syrup Category=Condiments UnitPrice=10 UnitsInStock=13
Category=Produce CheapestProducts=...
CheapestProducts: ProductID=74 ProductName=Longlife Tofu Category=Produce UnitPrice=10 UnitsInStock=4
Category=Meat/Poultry CheapestProducts=...
CheapestProducts: ProductID=54 ProductName=Tourtière Category=Meat/Poultry UnitPrice=7.45 UnitsInStock=21
Category=Seafood CheapestProducts=...
CheapestProducts: ProductID=13 ProductName=Konbu Category=Seafood UnitPrice=6 UnitsInStock=24
Category=Dairy Products CheapestProducts=...
CheapestProducts: ProductID=33 ProductName=Geitost Category=Dairy Products UnitPrice=2.5 UnitsInStock=112
Category=Confections CheapestProducts=...
CheapestProducts: ProductID=19 ProductName=Teatime Chocolate Biscuits Category=Confections UnitPrice=9.2
UnitsInStock=25
Category=Grains/Cereals CheapestProducts=...
CheapestProducts: ProductID=52 ProductName=Filo Mix Category=Grains/Cereals UnitPrice=7 UnitsInStock=38
//c#
public void Linq85()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int maxNum = numbers.Max();
Console.WriteLine("The maximum number is {0}.", maxNum);
}//JavaScript
function linq85() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var maxNum = Math.max.apply(null, numbers);
console.log("The maximum number is " + maxNum + ".");
}The maximum number is 9.
//c#
public void Linq86()
{
string[] words = { "cherry", "apple", "blueberry" };
int longestLength = words.Max(w => w.Length);
Console.WriteLine("The longest word is {0} characters long.", longestLength);
}//JavaScript
function linq86() {
var words = ["cherry", "apple", "blueberry"];
var longestLength = Math.max.apply(null, words.map(function(w) {
return w.length;
}));
console.log("The longest word is " + longestLength + " characters long.");
}The longest word is 9 characters long.
//c#
public void Linq87()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
select new { Category = g.Key, MostExpensivePrice = g.Max(p => p.UnitPrice) };
ObjectDumper.Write(categories);
}//JavaScript
function linq87() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g) {
return {
category: g.key,
mostExpensivePrice: Math.max.apply(null, g.values.map(function(p) {
return p.UnitPrice;
}))
};
});
categories.forEach(function(p) {
console.log("Category=" + p.category + " MostExpensivePrice=" + p.mostExpensivePrice);
});
}Category=Beverages MostExpensivePrice=263.5
Category=Condiments MostExpensivePrice=43.9
Category=Produce MostExpensivePrice=53
Category=Meat/Poultry MostExpensivePrice=123.79
Category=Seafood MostExpensivePrice=62.5
Category=Dairy Products MostExpensivePrice=55
Category=Confections MostExpensivePrice=81
Category=Grains/Cereals MostExpensivePrice=38
//c#
public void Linq88()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
let maxPrice = g.Max(p => p.UnitPrice)
select new { Category = g.Key, MostExpensiveProducts = g.Where(p => p.UnitPrice == maxPrice) };
ObjectDumper.Write(categories, 1);
}//JavaScript
function linq88() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g) {
var maxPrice = Math.max.apply(null, g.values.map(function(p) {
return p.UnitPrice;
}));
return {
category: g.key,
mostExpensiveProducts: g.values.filter(function(p) {
return p.UnitPrice === maxPrice;
})
};
});
categories.forEach(function(g) {
console.log("Category=" + g.category + " MostExpensiveProducts=...");
g.mostExpensiveProducts.forEach(function(p) {
console.log("MostExpensiveProducts: ProductID=" + p.ProductID + " ProductName=" + p.ProductName +
" Category=" + p.Category + " UnitPrice=" + p.UnitPrice + " UnitsInStock=" + p.UnitsInStock);
});
});
}Category=Beverages MostExpensiveProducts=...
MostExpensiveProducts: ProductID=38 ProductName=Côte de Blaye Category=Beverages UnitPrice=263.5 UnitsInStock=17
Category=Condiments MostExpensiveProducts=...
MostExpensiveProducts: ProductID=63 ProductName=Vegie-spread Category=Condiments UnitPrice=43.9 UnitsInStock=24
Category=Produce MostExpensiveProducts=...
MostExpensiveProducts: ProductID=51 ProductName=Manjimup Dried Apples Category=Produce UnitPrice=53 UnitsInStock=20
Category=Meat/Poultry MostExpensiveProducts=...
MostExpensiveProducts: ProductID=29 ProductName=Thüringer Rostbratwurst Category=Meat/Poultry UnitPrice=123.79
UnitsInStock=0
Category=Seafood MostExpensiveProducts=...
MostExpensiveProducts: ProductID=18 ProductName=Carnarvon Tigers Category=Seafood UnitPrice=62.5 UnitsInStock=42
Category=Dairy Products MostExpensiveProducts=...
MostExpensiveProducts: ProductID=59 ProductName=Raclette Courdavault Category=Dairy Products UnitPrice=55
UnitsInStock=79
Category=Confections MostExpensiveProducts=...
MostExpensiveProducts: ProductID=20 ProductName=Sir Rodney's Marmalade Category=Confections UnitPrice=81
UnitsInStock=40
Category=Grains/Cereals MostExpensiveProducts=...
MostExpensiveProducts: ProductID=56 ProductName=Gnocchi di nonna Alice Category=Grains/Cereals UnitPrice=38
UnitsInStock=21
//c#
public void Linq89()
{
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
double averageNum = numbers.Average();
Console.WriteLine("The average number is {0}.", averageNum);
}//JavaScript
function linq89() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var averageNum = numbers.reduce(function(sum, number) {
return sum + number;
}, 0) / numbers.length;
console.log("The average number is " + averageNum + ".");
}The average number is 4.5.
//c#
public void Linq90()
{
string[] words = { "cherry", "apple", "blueberry" };
double averageLength = words.Average(w => w.Length);
Console.WriteLine("The average word length is {0} characters.", averageLength);
}//JavaScript
function linq90() {
var words = ["cherry", "apple", "blueberry"];
var averageLength = words.reduce(function(sum, word) {
return sum + word.length;
}, 0) / words.length;
console.log("The average word length is " + averageLength + " characters.");
}The average word length is 6.666666666666667 characters.
//c#
public void Linq91()
{
List<Product> products = GetProductList();
var categories =
from p in products
group p by p.Category into g
select new { Category = g.Key, AveragePrice = g.Average(p => p.UnitPrice) };
ObjectDumper.Write(categories);
}//JavaScript
function linq91() {
var products = getProductList();
var categories = products.reduce(function(array, p) {
var key = p.Category;
var hasKey = array.some(function(item) {
return item.key === key ? ((item.values.push(p)), true) : false;
});
if(!hasKey){
array.push({ key: key, values: [p] });
}
return array;
}, []).map(function(g, index) {
return {
category: g.key,
averagePrice: g.values.reduce(function(sum, product) {
return sum + product.UnitPrice;
}, 0) / g.values.length
};
});
categories.forEach(function(p) {
console.log("Category=" + p.category + " AveragePrice=" + p.averagePrice);
});
}Category=Beverages AveragePrice=37.979166666666664
Category=Condiments AveragePrice=23.0625
Category=Produce AveragePrice=32.37
Category=Meat/Poultry AveragePrice=54.00666666666667
Category=Seafood AveragePrice=20.6825
Category=Dairy Products AveragePrice=28.73
Category=Confections AveragePrice=25.16
Category=Grains/Cereals AveragePrice=20.25
//c#
public void Linq92()
{
double[] doubles = { 1.7, 2.3, 1.9, 4.1, 2.9 };
double product = doubles.Aggregate((runningProduct, nextFactor) => runningProduct * nextFactor);
Console.WriteLine("Total product of all numbers: {0}", product);
}//JavaScript
function linq92() {
var doubles = [1.7, 2.3, 1.9, 4.1, 2.9];
var product = doubles.reduce(function(runningProduct, nextFactor) {
return runningProduct * nextFactor;
}, 1);
console.log("Total product of all numbers: " + product);
}Total product of all numbers: 88.33080999999999
//c#
public void Linq93()
{
double startBalance = 100.0;
int[] attemptedWithdrawals = { 20, 10, 40, 50, 10, 70, 30 };
double endBalance =
attemptedWithdrawals.Aggregate(startBalance,
(balance, nextWithdrawal) =>
((nextWithdrawal <= balance) ? (balance - nextWithdrawal) : balance));
Console.WriteLine("Ending balance: {0}", endBalance);
}//JavaScript
function linq93() {
var startBalance = 100.0;
var attemptedWithdrawals = [20, 10, 40, 50, 10, 70, 30];
var endBalance = attemptedWithdrawals.reduce(function(balance, nextWithdrawal) {
return nextWithdrawal <= balance ? (balance - nextWithdrawal) : balance;
}, startBalance);
console.log("Ending balance: " + endBalance);
}Ending balance: 20
//c#
public void Linq94()
{
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
var allNumbers = numbersA.Concat(numbersB);
Console.WriteLine("All numbers from both arrays:");
foreach (var n in allNumbers)
{
Console.WriteLine(n);
}
}//JavaScript
function linq94() {
var numbersA = [0, 2, 4, 5, 6, 8, 9];
var numbersB = [1, 3, 5, 7, 8];
var allNumbers = numbersA.concat(numbersB);
console.log("All numbers from both arrays:");
allNumbers.forEach(function(n) {
console.log(n);
});
}All numbers from both arrays:
0
2
4
5
6
8
9
1
3
5
7
8
//c#
public void Linq95()
{
List<Customer> customers = GetCustomerList();
List<Product> products = GetProductList();
var customerNames =
from c in customers
select c.CompanyName;
var productNames =
from p in products
select p.ProductName;
var allNames = customerNames.Concat(productNames);
Console.WriteLine("Customer and product names:");
foreach (var n in allNames)
{
Console.WriteLine(n);
}
}//JavaScript
function linq95() {
var customers = getCustomerList();
var products = getProductList();
var customerNames = customers.map(function(c) {
return c.CompanyName;
});
var productNames = products.map(function(p) {
return p.ProductName;
});
var allNames = customerNames.concat(productNames);
console.log("Customer and product names:");
allNames.forEach(function(n) {
console.log(n);
});
}Customer and product names:
Alfreds Futterkiste
Ana Trujillo Emparedados y helados
Antonio Moreno Taquería
Around the Horn
Berglunds snabbköp
Blauer See Delikatessen
...
//c#
public void Linq96()
{
var wordsA = new string[] { "cherry", "apple", "blueberry" };
var wordsB = new string[] { "cherry", "apple", "blueberry" };
bool match = wordsA.SequenceEqual(wordsB);
Console.WriteLine("The sequences match: {0}", match);
}//JavaScript
function linq96() {
var wordsA = ["cherry", "apple", "blueberry"];
var wordsB = ["cherry", "apple", "blueberry"];
var match = wordsA.length === wordsB.length &&
wordsA.every(function(w, index) {
return w === wordsB[index];
});
console.log("The sequences match: " + match);
}The sequences match: true
//c#
public void Linq97()
{
var wordsA = new string[] { "cherry", "apple", "blueberry" };
var wordsB = new string[] { "apple", "blueberry", "cherry" };
bool match = wordsA.SequenceEqual(wordsB);
Console.WriteLine("The sequences match: {0}", match);
}//JavaScript
function linq97() {
var wordsA = ["cherry", "apple", "blueberry"];
var wordsB = ["apple", "blueberry", "cherry"];
var match = wordsA.length === wordsB.length &&
wordsA.every(function(w, index) {
return w === wordsB[index];
});
console.log("The sequences match: " + match);
}The sequences match: false
//c#
public static class CustomSequenceOperators
{
public static IEnumerable Combine(this IEnumerable first, IEnumerable second,
Func func) {
using (IEnumerator e1 = first.GetEnumerator(), e2 = second.GetEnumerator())
{
while (e1.MoveNext() && e2.MoveNext()) {
yield return func(e1.Current, e2.Current);
}
}
}
}
public void Linq98() {
int[] vectorA = { 0, 2, 4, 5, 6 };
int[] vectorB = { 1, 3, 5, 7, 8 };
int dotProduct = vectorA.Combine(vectorB, (a, b) => a * b).Sum();
Console.WriteLine("Dot product: {0}", dotProduct);
}//JavaScript
function linq98() {
var vectorA = [0, 2, 4, 5, 6];
var vectorB = [1, 3, 5, 7, 8];
var dotProduct = vectorA.map(function(a, index) {
return a * vectorB[index];
}).reduce(function(sum, number) {
return sum + number;
}, 0);
console.log("Dot product: " + dotProduct);
}Dot product: 109
//c#
public void Linq99()
{
// Sequence operators form first-class queries that
// are not executed until you enumerate over them.
int[] numbers = new int[] { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int i = 0;
var q =
from n in numbers
select ++i;
// Note, the local variable 'i' is not incremented
// until each element is evaluated (as a side-effect):
foreach (var v in q)
{
Console.WriteLine("v = {0}, i = {1}", v, i);
}
}//JavaScript
function linq99() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var i = 0;
var q = numbers.map(function() {
return function() {
return ++i;
};
});
q.forEach(function(v) {
console.log("v = " + v() + " i = " + i);
});
}v = 1 i = 1
v = 2 i = 2
v = 3 i = 3
v = 4 i = 4
v = 5 i = 5
v = 6 i = 6
v = 7 i = 7
v = 8 i = 8
v = 9 i = 9
v = 10 i = 10
//c#
public void Linq100()
{
// Methods like ToList() cause the query to be
// executed immediately, caching the results.
int[] numbers = new int[] { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
int i = 0;
var q = (
from n in numbers
select ++i)
.ToList();
// The local variable i has already been fully
// incremented before we iterate the results:
foreach (var v in q)
{
Console.WriteLine("v = {0}, i = {1}", v, i);
}
} //JavaScript
function linq100(){
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var i = 0;
var q = numbers.map(function() {
return ++i;
});
q.forEach(function(v) {
console.log("v = " + v + " i = " + i);
});
}v = 1 i = 10
v = 2 i = 10
v = 3 i = 10
v = 4 i = 10
v = 5 i = 10
v = 6 i = 10
v = 7 i = 10
v = 8 i = 10
v = 9 i = 10
v = 10 i = 10
//c#
public void Linq101()
{
// Deferred execution lets us define a query once
// and then reuse it later after data changes.
int[] numbers = new int[] { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var lowNumbers =
from n in numbers
where n <= 3
select n;
Console.WriteLine("First run numbers <= 3:");
foreach (int n in lowNumbers)
{
Console.WriteLine(n);
}
for (int i = 0; i < 10; i++)
{
numbers[i] = -numbers[i];
}
// During this second run, the same query object,
// lowNumbers, will be iterating over the new state
// of numbers[], producing different results:
Console.WriteLine("Second run numbers <= 3:");
foreach (int n in lowNumbers)
{
Console.WriteLine(n);
}
} //JavaScript
function linq101() {
var numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
var lowNumbers = function(){
return numbers.filter(function(n){
return n <= 3;
});
};
console.log("First run numbers <= 3:")
lowNumbers().forEach(function(n) {
console.log(n);
});
for (var i = 0; i < 10; i++) {
numbers[i] = -numbers[i];
}
console.log("Second run numbers <= 3:");
lowNumbers().forEach(function(n) {
console.log(n);
});
}First run numbers <= 3:
1
3
2
0
Second run numbers <= 3:
-5
-4
-1
-3
-9
-8
-6
-7
-2
0
//c#
public void Linq102()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category
select new { Category = c, p.ProductName };
foreach (var v in q)
{
Console.WriteLine(v.ProductName + ": " + v.Category);
}
}//JavaScript
function linq102() {
var categories = ["Beverages", "Condiments", "Vegetables", "Dairy Products", "Seafood"];
var products = getProductList();
var q = categories.reduce(function(array, c) {
products.filter(function(p) {
return c === p.Category;
}).forEach(function(p) {
array.push({
category: c,
productName: p.ProductName
});
});
return array;
}, []);
q.forEach(function(v) {
console.log(v.productName + ": " + v.category);
});
}Chai: Beverages
Chang: Beverages
Guaraná Fantástica: Beverages
Sasquatch Ale: Beverages
Steeleye Stout: Beverages
Côte de Blaye: Beverages
Chartreuse verte: Beverages
Ipoh Coffee: Beverages
Laughing Lumberjack Lager: Beverages
Outback Lager: Beverages
...
//c#
public void Linq103()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category into ps
select new { Category = c, Products = ps };
foreach (var v in q)
{
Console.WriteLine(v.Category + ":");
foreach (var p in v.Products)
{
Console.WriteLine(" " + p.ProductName);
}
}
}//JavaScript
function linq103() {
var categories = ["Beverages", "Condiments", "Vegetables", "Dairy Products", "Seafood"];
var products = getProductList();
var q = categories.reduce(function(array, c) {
var ps = products.filter(function(p) {
return c === p.Category;
});
array.push({
category: c,
products: ps
});
return array;
}, []);
q.forEach(function(v) {
console.log(v.category + ":");
v.products.forEach(function(p) {
console.log(" " + p.ProductName);
});
});
}Beverages:
Chai
Chang
Guaraná Fantástica
Sasquatch Ale
Steeleye Stout
Côte de Blaye
Chartreuse verte
Ipoh Coffee
Laughing Lumberjack Lager
Outback Lager
Rhönbräu Klosterbier
Lakkalikööri
Condiments:
Aniseed Syrup
Chef Anton's Cajun Seasoning
Chef Anton's Gumbo Mix
Grandma's Boysenberry Spread
Northwoods Cranberry Sauce
Genen Shouyu
Gula Malacca
Sirop d'érable
Vegie-spread
Louisiana Fiery Hot Pepper Sauce
Louisiana Hot Spiced Okra
Original Frankfurter grüne Soße
...
//c#
public void Linq104()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category into ps
from p in ps
select new { Category = c, p.ProductName };
foreach (var v in q)
{
Console.WriteLine(v.ProductName + ": " + v.Category);
}
}//JavaScript
function linq104() {
var categories = ["Beverages", "Condiments", "Vegetables", "Dairy Products", "Seafood"];
var products = getProductList();
var q = categories.reduce(function(array, c) {
var ps = products.filter(function(p) {
return c === p.Category;
});
ps.forEach(function(p) {
array.push({
category: c,
productName: p.ProductName
});
});
return array;
}, []);
q.forEach(function(v) {
console.log(v.productName + ": " + v.category);
});
}Chai: Beverages
Chang: Beverages
Guaraná Fantástica: Beverages
Sasquatch Ale: Beverages
Steeleye Stout: Beverages
Côte de Blaye: Beverages
Chartreuse verte: Beverages
Ipoh Coffee: Beverages
Laughing Lumberjack Lager: Beverages
Outback Lager: Beverages
Rhönbräu Klosterbier: Beverages
Lakkalikööri: Beverages
Aniseed Syrup: Condiments
Chef Anton's Cajun Seasoning: Condiments
Chef Anton's Gumbo Mix: Condiments
...
//c#
public void Linq105()
{
string[] categories = new string[]{
"Beverages",
"Condiments",
"Vegetables",
"Dairy Products",
"Seafood" };
List<Product> products = GetProductList();
var q =
from c in categories
join p in products on c equals p.Category into ps
from p in ps.DefaultIfEmpty()
select new { Category = c, ProductName = p == null ? "(No products)" : p.ProductName };
foreach (var v in q)
{
Console.WriteLine(v.ProductName + ": " + v.Category);
}
}//JavaScript
function linq105(){
var categories = ["Beverages", "Condiments", "Vegetables", "Dairy Products", "Seafood"];
var products = getProductList();
var q = categories.reduce(function(array, c) {
var ps = products.filter(function(p) {
return c === p.Category;
});
if(ps.length) {
ps.forEach(function(p) {
array.push({
category: c,
productName: p.ProductName
});
});
} else {
array.push({
category: c,
productName: "(No products)"
});
}
return array;
}, []);
q.forEach(function(v) {
console.log(v.productName + ": " + v.category);
});
}Chai: Beverages
Chang: Beverages
Guaraná Fantástica: Beverages
Sasquatch Ale: Beverages
Steeleye Stout: Beverages
Côte de Blaye: Beverages
Chartreuse verte: Beverages
Ipoh Coffee: Beverages
Laughing Lumberjack Lager: Beverages
Outback Lager: Beverages
Rhönbräu Klosterbier: Beverages
Lakkalikööri: Beverages
Aniseed Syrup: Condiments
Chef Anton's Cajun Seasoning: Condiments
Chef Anton's Gumbo Mix: Condiments
Grandma's Boysenberry Spread: Condiments
Northwoods Cranberry Sauce: Condiments
Genen Shouyu: Condiments
Gula Malacca: Condiments
Sirop d'érable: Condiments
Vegie-spread: Condiments
Louisiana Fiery Hot Pepper Sauce: Condiments
Louisiana Hot Spiced Okra: Condiments
Original Frankfurter grüne Soße: Condiments
(No products): Vegetables
...