1. Introduction to JavaScript!!

Image Credits : Wikimedia Commons

Why JavaScript?

JavaScript is the most sought language in today’s world. The Most versatile language, that can be used to create a wide variety of applications : Web-apps, Mobile-apps, Desktop-apps, Server-Side Apps.

About JavaScript:

1. JavaScript was designed by Brendan Eich in 1995
2. JavaScript is Single-threaded Non-Blocking Asynchronous Concurrent Language, having a call-stack, event-Loop, callback-queue & some APIs.
3. JavaScript is a Prototype Based Language. (In JavaScript, Inheritance is through prototype mechanism. In it, properties & methods can be added to any object dynamically.)
4. Is JavaScript is “INTERPRETED” Language? —The common assumption is that, it is interpreted, because JavaScript source code is processed each time it’s run in the engine. But it is not entirely accurate. The JavaScript engine actually compiles the program on the fly (in-time compilation) and then immediately runs the compiled code.
5. JavaScript Behaviour & Performance depends on the JS engine that lies behind the browser.
6. JavaScript is the implementation of ECMA SCRIPT specification.
7. JavaScript is a “case-sensitive” language.

About ECMA SCRIPT (ES)

1. Designed by Brendan Eich.
2. It is a blueprint for creating a scripting language.
3. The JavaScript Standard to ensure the interoperability between web pages across different Browsers.
4. Latest Edition — ES 13 (2022)
5. Most Notable Release or Standard— ES 6 (2015) — Most of the features were introduced in this release.

The JavaScript Engine

1. Basically a standard interpreter or compiler, that compiles JavaScript code.
2. All relevant modern engines use just in time compilation for improved performance.
3. In web browser, JS engine runs in session with the JS rendering engine via DOM (Document Object Model).
4. Although JS engine is mostly used in Web Browsers, but its not only limited to browsers. Node.js uses V8 JavaScript engine.

JavaScript Engines Used by various browsers

1. Chrome — Most Powerful — Uses V8 Engine — Most Faster JS Engine, as of now. (V8 is Google’s Open Source high performance JavaScript engine written in C++.)
2. Firefox — Uses SpiderMonkey.
3. Safari — Uses JavaScriptCore.
4. Internet Explorer (now expired) — Used Chakra.
5. Microsoft Edge — Firstly it used Chakra, but later it was rebuilt as Chromium-based browser & now it uses V8 engine.

Happy JavaScript Learning & Coding!😀

Thanks for reading :) That’s it, I hope you liked the article.

Who am I to write?

Just a curious Learner, who loves to develop websites, and have developed few websites using various templates, using React (from scratch) as well, most of them as personal projects or college club sites, since past 3–4 years. In short, I have worked on React, JavaScript, CSS & HTML and still learning new things daily!

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