Introduction to JavaScript

Introduction to JavaScript

JavaScript is a scripting language of the web that allows you to do/add Interactivity with User-Events, implement Conditions and Validations, Dynamic updates in a Web Page, etc.. In this practical course will learn JavaScript basics-programming fundamentals from scratch. We Will start with what is JavaScript? its uses, history, how to write JavaScript, etc. It will also cover various programming building blocks like variable, functions, array, conditionals, objects, and many more.

Prerequisites to Start Learning JavaScript:

To move forward with JavaScript you just need basic knowledge of XHTML/HTML. Here, you will learn how easy it is to add interactivity to a web page using JavaScript. But, before we begin, make sure that you have some working knowledge and/or general understanding of:

  • The Internet and the World Wide Web
  • Good Knowledge of HTML5 Essentials and
  • Knowledge of CSS3 Fundamentals

Who is this for?

This course is for any Web Designer, Developer who is interested in dynamic Web Development with JavaScript. Anyone who wants to make a career in Web Development or planning on being a front-end developer must learn JavaScript.

Let’s start by Understanding what JavaScript is

What is JavaScript?

  • JavaScript is 1 of the 3 core language/layers of web…(HTML, CSS & JavaScript)
  • JavaScript is one of the most popular, widely used, lightweight scripting programming language
  • JavaScript is an Open Source, Cross-Platform, and Browser-based Client-Side (user computer) programming language of the web
  • JavaScript is a dynamic computer programming language. It is an interpreted (translated) programming language with object-oriented capabilities
  • JavaScript is officially maintained by ECMA (European Computer Manufacturers Association) as ECMAScript
  • ECMAScript 6 (or ES6 or ECMAScript 2015) is the latest major version of the ECMAScript standard
  • JavaScript is case sensitive language.
Stackoverflow Programming, Scripting, and Markup Languages Survey 2023
Stackoverflow Programming, Scripting, and Markup Languages Survey 2023

What is a scripting language?

A high-level programming language that is interpreted by another program at runtime rather than compiled by the computer’s processor as other programming languages. The simple difference between scripting language and programming language is: Scripting languages do not require the compilation step and are rather interpreted

  • C program needs to be compiled before running whereas normally, a scripting language like JavaScript or PHP need not be compiled.

If you want to know what script is? Than Script is nothing but sets of instructions or you can say a series of commands.

What can you do with JavaScript?

JavaScript enables you to build interactive websites, adding functionality to web pages such as forms validation, dynamic content updates and more. 

Use of JavaScript

For a long time, JavaScript is used only as a Client Side Front End Development language to build browser-based interactive web pages. But currently due to huge community support (Node or Nide.js) JavaScript is multi-purpose language and used to develop:

  • Full-fledged Enterprise Web Application
  • Full-blown Mobile Apps
  • Real-time Networking Apps (Chats, Audio/Video Streaming Services)
  • Games
  • Command Line Tools (CLI-Command Line Interface utilities)

Where does the JavaScript code run?

JavaScript was originally designed and developed to run only in browsers. But now with the help of the Node/Node.js (C++ program, that includes Google's V8 JavaScript engine) we can build the back-end(server-side) for our web and mobile applications.

Common JavaScript Browser Engines

BrowserEngine
Browser, Headless Browser, or RuntimeJavaScript Engine
MozillaSpidermonkey
Safari**JavaScriptCore*
IE and EdgeChakra
ChromeV8
TrifleJSV8
Node.js***V8
Io.js***V8
PhantomJSJavaScriptCore
HTMLUnitRhino

Who are using JavaScript?

  • JavaScript is used by:

    • Front-end Developer
    • Back-end Developer
    • Full-stack Developer
  • Big companies and brands build entire applications:

    • Netflix
    • Walmart
    • PayPal
    • Microsoft
    • Facebook (React.js)
    • Google (Angular.js)
    • Ebay
    • Uber
    • Groupon

History of JavaScript

  • Invented by “Brandan Eich” at Netscape in 1995 originally named as "LiveScript"
  • Netscape & Sun Java agreements to rename "LiveScript" to "JavaScript" (As java is already popular in the market)
  • Not at-all related to JAVA (completely different in concept and design)
  • Microsoft has developed new version of “JavaScript” as "JScript" for IE-3 in 1996
  • JavaScript Submitted to ECMAScript in 1997

JavaScript Vs ECMAScript

JavaScriptECMAScript
JavaScript is scripting programming languageECMAScript is a specification/standard
JavaScript is invented by Brandan Eich at NetscapeECMAScript standards defined by ECMA (European Computer Manufacturers Association)
JavaScript is released in 1995First ECMAScript standard published in 1997
JavaScript uses/follows ECMAScript specifications/standardsECMAScript specification defines many new features for JavaScript