Introduction to JavaScript

What is JavaScript

JavaScript is a high-level, interpreted programming/scripting language.

It conforms to the ECMAScript specification.

It’s a multi-paradigm language.

Originally it was a client side language but now can run on server side(Node JS).

Why JavaScript ?

Web Page      –        HTML

Design            –        CSS

Interactive     –        JavaScript (popups, validations, actions)

It is the programming language of browser.

To build mobile application.(React Native, NativeScript, Ionic)

To build very interactive Website UI(React, AngularJS).

To Build Website Backend and full stack applications also.(using NodeJS)

ECMA International

An organization that creates standards for technologies.


ECMA-262

This is a standard published by ECMA International. It contains the specification for a general-purpose scripting language.

ECMAScript

The specification defined in ECMA-262 for creating a general-purpose scripting language.

ECMAScript provides the rules, details, and guidelines that a scripting language must observe to be considered ECMAScript compliant.

It is a standard meant to ensure the interoperability of web pages across different web browsers.

ECMAScript 6

It is the sixth edition of the ECMA-262 standard and features major changes and improvements to the ECMAScript specification.

Some of the new features:

The let keyword

The Const keyword

Arrow functions

Map objects

Set objects

Promises

Classes

A JavaScript engine

A program or interpreter that understands and executes JavaScript code.

JavaScript engines are commonly found in web browsers.

 Two browsers can understand JavaScript code, but one may runs it faster because its JavaScript engine is implemented more efficiently.

A JavaScript runtime

The environment in which the JavaScript code runs and is interpreted by a JavaScript engine. The runtime provides the host objects that JavaScript can operate on and work with.

Please check below the Youtube video on Introduction to JavaScript. It invloves detailed explaination :