History of Java Script & What is JavaScript

JavaScript is a lightweight, interpreted, object-oriented language with first-class functions. This means that functions can be stored in variables and passed around like any other object. While JavaScript is best known as the scripting language for web pages, it’s also used in many non-browser environments. It’s a prototype-based, multi-paradigm scripting language that is dynamic, supporting object-oriented, imperative, and functional programming styles. JavaScript enables object-oriented programming with object prototypes, rather than classes (we’ll dive deeper into classes and prototypical inheritance later in this course).
Now, let's explore the history of JavaScript:
JavaScript was created in 1995 by Brendan Eich while he was an engineer at Netscape. It was first released with Netscape 2 in early 1996. Originally, it was going to be called LiveScript, but it was renamed to JavaScript in a marketing move to capitalize on the popularity of Sun Microsystems' Java language-despite the two having very little in common. This name change has caused confusion for many over the years.
A few months later, Microsoft released JScript with Internet Explorer 3, a mostly-compatible JavaScript alternative. Later that year, Netscape submitted JavaScript to Ecma International, a European standards organization, to standardize the language. This resulted in the first edition of the ECMAScript standard. The standard received a significant update with ECMAScript edition 3 in 1999. However, the fourth edition was abandoned due to political differences concerning language complexity. Many parts of the fourth edition formed the basis for ECMAScript edition 5, published in December 2009.
Then came ECMAScript edition 6, which we commonly refer to as ES6, in June 2015. Anytime you see "ES" used to describe JavaScript versions, it stands for ECMAScript. After ES5 and ES6, new editions are published every year. For example, ES6 is also known as ES2015, and the version released in 2016 is ES2016, and so on.
The JavaScript community is constantly evolving.
A wealth of useful libraries, frameworks, tools, and even languages are being developed to leverage and scale JavaScript. In 2006, the jQuery library was released, one of the first JS libraries to be well-documented and widely used to build complex, interactive applications that worked reliably across browsers.
In 2008, Google launched the V8 engine-an open-source, high-performance JavaScript and WebAssembly engine, written in C++. V8 revolutionized JavaScript by making it a viable option for high-performance applications. Following V8’s success, Node.js was launched in 2009 as a server-side runtime for JavaScript, built on the V8 engine.
In 2010, JavaScript frameworks specifically designed for single-page applications emerged, providing a seamless user experience. Backbone.js and AngularJS, both released in October of 2010, were significant players in this space. Backbone.js was lightweight and handled DOM updates with an imperative style, while AngularJS was more comprehensive and used a declarative style.
Languages derived from JavaScript:
Several languages, such as TypeScript and CoffeeScript, compile down to JavaScript. TypeScript is a superset of JavaScript, offering optional static typing, while CoffeeScript is an enhanced version of JavaScript. There are also other languages like Dart and Kotlin, which can be compiled into JavaScript.
JavaScript continues to evolve, but its old features remain intact.
Despite the numerous updates and additions to JavaScript, none of the older features are removed. This is because a lot of legacy code is still running on millions of devices and browsers. However, while it's important to know the older features, it's equally important to adopt newer, more optimized patterns and practices.
In this course, we’ll cover interesting features from ES2015 (ES6) to ES2022, as well as some of the older patterns and the challenges they present. We’ll also aim to keep this course updated with the latest features in future editions.
One more thing to keep in mind:
While writing JavaScript, it’s a good practice to use 'strict mode' at the top of your code. This helps catch errors that might otherwise go unnoticed. While I may not use 'use strict' in all the examples throughout the course, I use it in my own development projects, and I highly recommend you do the same to avoid unexpected errors.