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Regular expressions (RegExp):

a way to describe patterns in string data. They form a small, separate language that is part of JavaScript and many other languages and tools. RegExps are a powerful tool for inspecting and processing strings. Properly understanding regular expressions will make you a more effective programmer.

Events:

there is different types of events - browser, mouse, keyboard, focus events. It is a signal from related source that something has happened.

Event handlers:

They are JavaScript code that are not added inside the <script> tags, but rather, inside the html tags, that execute JavaScript when something happens, such as pressing a button, moving your mouse over a link, submitting a form etc. Example - onClick is an event handler:

  <button name="submit" onclick="validateForm(event)">
     Send your letter to Santa
  </button>

More on event handlers you can read here: http://www.javascriptkit.com/javatutors/event1.shtml

Event.preventDefault:

Prevents default behaviour of the events.

Refactoring:

is the process of restructuring existing computer code - changing the factoring - without changing its external behavior. Refactoring improves nonfunctional attributes of the software.

Objects:

stand-alone entities that have properties/type and functions

Constructors:

function that creates and initializes an object.The 'new' operator is used to create an instance of an object

Dot-notation:

uses dot operator '.' to access the properties of an object

Bracket-notation:

uses the "[]" operator to access the properties of an object

Callback:

A function that we pass inside of another function as an argument Example:

const a = ['a', 'b', 'c'];

a.forEach(function(element) {
    console.log(element);
});

Local storage:

function which allows the web pages to store information locally on to the client's web browser using key-value notation

Serialize an object :

converting an object to a string format. JSON.stringify() function is used to serialize an object

Deserialize:

converting a string to an object. JSON.parse() function is used to deserialize an object

JSON:

(JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is a way to store information in an organized, easy-to-access manner.

Math:

The JavaScript Math object allows you to perform mathematical tasks on numbers. It has properties and methods for mathematical constants and functions. Pi number, calculate sin, cos, random etc.

AJAX:

(Asynchronous JavaScript and XML) With it you can:

  • Update a web page without reloading the page
  • Request/receive data from a server - after the page has loaded
  • Send data to a server - in the background

Asynchronous JavaScript

Use callbacks to run functions asynchronously.