Purpose:

Notes from completing SoloLearn tutorials.

Proof of completion (SoloLearn certificates)

#	Course	Certificate
1	HTML	https://www.sololearn.com/Certificate/1014-18375186/jpg
2	CSS	https://www.sololearn.com/Certificate/1023-18375186/jpg
3	Responsive Web Design	https://www.sololearn.com/Certificate/1162-18375186/jpg
4	JavaScript	https://www.sololearn.com/certificates/course/en/18375186/1024/landscape/png
5	React+Redux	https://www.sololearn.com/Certificate/1097-18375186/jpg/
6	SQL	https://www.sololearn.com/certificates/course/en/18375186/1060/landscape/png
7	Python for Beginners	https://www.sololearn.com/certificates/course/en/18375186/1157/landscape/png
8	Python Core	https://www.sololearn.com/certificates/course/en/18375186/1073/landscape/png
9	Python Intermediate	https://www.sololearn.com/certificates/course/en/18375186/1158/landscape/png
10	Python Data Structures	https://www.sololearn.com/certificates/course/en/18375186/1159/landscape/png
11	Python for Data Science	https://www.sololearn.com/certificates/course/en/18375186/1161/landscape/png
12	Java

Favorite Key Takeaways ⭐

HTML

The HTML layout:
(Link to CSS in head, link to JavaScript last in footer. Load the HTML/CSS first, JavaScript takes longer and can load last).

<!DOCTYPE html>
<html>

<head>
  <meta charset='UTF-8'>
  <meta name='description' content='iVuDang'> 
  <meta name='keywords' content='iVuDang, Vu Dang'>
  <metaname='author' content='Vu Dang'>
  <meta name='viewport' content='width=device-width, initial-scale=1'>
  <title>iVuDang</title> 

  <meta property='og:title' content='Vu Dang, CPA'/>
  <meta property='og:image' content='https://ivudang.com/images/japan.JPG'/>
  <meta property='og:description' content='Website Portfolio built by Vu Dang'/>
  <meta property='og:url' content='https://www.ivudang.com/'/>
  <meta property="og:type" content="website" />

  <link href="styles/pg1-home.css" rel="stylesheet">
</head> 

<body>

  <main> 
  
    <article>
      <section> 
      </section> 
    </article>
    
  </main> 
 
  <footer> </footer> 
  
</body>

</html>

CSS

All HTML elements can be considered as boxes. The CSS box model represents the design and layout of the site. It consists of margins, borders, paddings, and the actual content.

Hence, it is a useful practice to initially set a colored border to visualize our box elements when in the early phases of structuring our web content e.g.:

  border: 2px solid red;

JavaScript

JavaScript variables are containers for data values. Objects are variables too, but they can contain many values.

Think of an object as a list of values that are written as name:value pairs, with the names and the values separated by colons.

let person = {
	name: 'John', 
	age: 31,
	favColor: 'green',
	height: 183
};

Can access age of our person in two ways:

object.name
object['name']

let x = person.age;
let y = person['age']

Output: 31

SQL

The syntax for the WHERE clause:

SELECT column_list 
FROM table_name 
WHERE condition

The LIKE keyword is useful when specifying a search condition within your WHERE clause.

In relationship databases, a piece of string data should only appear once (avoid redundant data, it should only appear once in a table and linked to other tables). Keys are ideally integers e.g. ID.

Additional Supplement from: https://www.w3schools.com/sql/sql_like.asp

There are two wildcards often used in conjunction with the LIKE operator:

The percent sign (%) represents zero, one, or multiple characters
The underscore sign (_) represents one, single character

WHERE CustomerName LIKE 'a%' 	Finds any values that start with "a"
WHERE CustomerName LIKE '%a' 	Finds any values that end with "a"
WHERE CustomerName LIKE '%or%' 	Finds any values that have "or" in any position
WHERE CustomerName LIKE '_r%' 	Finds any values that have "r" in the second position
WHERE CustomerName LIKE 'a_%' 	Finds any values that start with "a" and are at least 2 characters in length
WHERE CustomerName LIKE 'a__%' 	Finds any values that start with "a" and are at least 3 characters in length
WHERE ContactName LIKE 'a%o' 	Finds any values that start with "a" and ends with "o"

Python

Python supports the following data structures: lists, dictionaries, tuples, sets.

Data Structure	Ordered	Mutable	Constructor	Example
List	Yes	Yes	[ ]	[1, 2, 3]
Tuple	Yes	No	( )	(1, 2, 3)
Set	No	Yes	{ }	{1, 2, 3}
Dictionary	No	Yes	{ }	{'One': 1, 'Two': 2, 'Three': 3}

When to use a dictionary:

When you need a logical association between a key:value pair.
When you need fast lookup for your data, based on a custom key.
When your data is being constantly modified. Remember, dictionaries are mutable.

When to use the other types:

Use lists if you have a collection of data that does not need random access. Try to choose lists when you need a simple, iterable collection that is modified frequently.
Use a set if you need uniqueness for the elements.
Use tuples when your data cannot change. Many times, a tuple is used in combination with a dictionary, for example, a tuple might represent a key, because it's immutable.

iVuDang/SoloLearn-HTML-layout-Python-list-tuple-set-dictionary