Lotide

A mini clone of the Lodash library.

Purpose

BEWARE: This library was published for learning purposes. It is not intended for use in production-grade software.

This project was created and published by me as part of my learnings at Lighthouse Labs.

Usage

Install it:

npm install @jcarloflores/lotide

Require it:

const _ = require('@jcarloflores/lotide');

Call it:

const results = _.tail([1, 2, 3]) // => [2, 3]

Documentation

The following functions are currently implemented:

countLetters(sentence): Returns an object with key-value pairs with a total count for each letter.

Since
- 1.0.1
Arguments
- sentence (String): The string to process.
Returns
- (Object): Returns an object with key-value pair summary per letter.
Example
```
_.countLetters('Hello World');
// => { h: 1, 
//      e: 1, 
//      l: 3, 
//      o: 2, 
//      w: 1, 
//      r: 1, 
//      d: 1 }
```
countOnly(allItems, itemsToCount): Returns an object with key-value pair count based on itemsToCount object of matching key and boolean value of true.

Since
- 1.0.1
Arguments
- allItems (Array): Array of strings to process.
- itemsToCount (Object): Object with keys of what to count paired with boolean values.
Returns
- (Object): Returns an object with key-value pair count for each matching key with true values.
Example
```
const firstNames = [
  "Hello",
  "World",
  "Foo",
  "Bar",
  "Code",
  "World",
  "Bar",
];

_.countOnly(firstNames, { World: true, Blaster: true, Bar: false});
// => { World: 2 }
```
eqArrays(array1, array2): Returns a boolean value depending whether or not both arrays are strictly equal to each other.

Since
- 1.0.1
Arguments
- array1 (Array): First array for comparison.
- array2 (Array): Second array for comparison.
Returns
- (Boolean): Returns an boolean value (true or false) if both arrays are strictly equal.
Example
```
const array1 = [1, [2], 3];
const array2 = [1, [2], 3];

_.eqArrays(array1, array2);
// => true
```
eqObjects(object1, object2): Returns a boolean value depending whether or not both objects are strictly equal to each other.

Since
- 1.0.1
Arguments
- object1 (Object): First object for comparison.
- object2 (Object): Second object for comparison.
Returns
- (Boolean): Returns an boolean value (true or false) if both objects are strictly equal.
Example
```
const object1 = {a: 1, b: {c: 2}, d: 2};
const object2 = {a: 1, d: 2, b: {c: 2}};

_.eqObjects(object1, object2);
// => true
```
findKey(object, callback): Returns key of object if the value of the key is truthy when using with the callback.

Since
- 1.0.1
Arguments
- object (Object): The object to evaluate.
- callback (Function): Callback function that takes in object[key] as argument.
Returns
- (Object): Returns first key with truthy callback(value).
Example
```
const toys = () => {
  "car":     { shelflife: 3},
  "ball":    { shelflife: 2},
  "doll":    { shelflife: 4),
  "device":  { shelflife: 2},
  "top":     { shelflife: 5},
}

_.findKey(toys, toy =>  toy.shelflife === 2);
// => "ball"
```
flatten(array): Returns an array without any nesting.

Since
- 1.0.1
Arguments
- array (Array): The array to evaluate.
Returns
- (Object): Returns flattened array.
Example
```
const array = [1, 2, [3, 4], 5, [6]];

_.flatten(array);
// => [1, 2, 3, 4, 5, 6]
```
head(array): Returns the first item in the array.

Since
- 1.0.0
Arguments
- array (Array): The array to process.
Returns
- (Array): Returns the first element of array.
Example
```
_.head(['a', 'b', 'c']);
// => 'a'

_.head([1, 2, 3]);
// => 1
```
letterPositions(sentence): Returns an object with key-value pairs that correspond to the index locations of each letter from provided string.

Since
- 1.0.1
Arguments
- sentence (String): The string to evaluate.
Returns
- (Object): Returns object index locations of each letter in the sentence.
Example
```
const sentence = "hello";

_.letterPositions(sentence);
  // => { h: [0], 
  //      e: [1], 
  //      l: [2, 3], 
  //      o: [4] }
```
map(array, callback): Returns a new array with each value modified based on the callback.

Since
- 1.0.1
Arguments
- array (Array): The array to evaluate.
- callback (Function): Callback function that modifies each object[key].
Returns
- (Object): Returns new array where each value has been modified by the callback function.
Example
```
const numbers = [1, 2, 3, 4, 5];
_.map(numbers, n => n * 2);
// => [2, 4, 6, 8, 10]
```
middle(array): Returns the middle item of the first of the array.

Since
- 1.0.0
Arguments
- array (Array): The array to process.
Returns
- (Array): Returns the middle element of array. If the array length is even, it will return two elements.
Example
```
_.middle(['a', 'b', 'c']);
// => 'b'

_.middle([1, 2, 3, 4]);
// => '[2, 3]
```
tail(array): Returns every item in the array except the first item (head).

Since
- 1.0.0
Arguments
- array (Array): The array to process.
Returns
- (Array): Returns every item in an array except the first item.
Example
```
_.tail(['a', 'b', 'c']);
// => ['b', 'c']

_.tail([1, 2, 3, 4]);
// => '[2, 3, 4]
```
takeUntil(array, callback): Evaluates each element starting from the beginning until callback evaluates true.

Since
- 1.0.1
Arguments
- array (Array): The array to evaluate.
- callback (Function): Callback function that evaluates each element.
Returns
- (Array): Returns new array with elements up till element satisfies callback condition.
Example
```
const array = [1, 2, 5, 7, 2, -1, 2, 4, 5];
_.takeUntil(array, x => x < 0);
// => [ 1, 2, 5, 7, 2 ]
```
without(source, itemsToRemove): Evaluates each element in the array and removes elements that match itemsToRemove.

Since
- 1.0.1
Arguments
- source (Array): The array to evaluate.
- itemsToRemove (Array): The array containing elements to compare for removal.
Returns
- (Array): Returns new array with elements that do not contain itemsToRemove.
Example
```
const array = [1, 2, 3];
_.without(array, [1]);
// => [2, 3]
```

john-carlo-flores/lotide

Lotide

Purpose

Usage

Documentation