JavaScript - History & Versions
Overview
Estimated time: 15–20 minutes
JavaScript has evolved through many versions, each adding new features and standards. Understanding version history helps you write compatible and modern code.
Learning Objectives
- Recognize major JavaScript/ECMAScript versions.
- Identify key features introduced in each version.
Prerequisites
ECMAScript Timeline
| Year | Version | Key Features |
|---|---|---|
| 1997 | ES1 | First edition |
| 1998 | ES2 | Editorial changes |
| 1999 | ES3 | Regular expressions, try/catch |
| 2009 | ES5 | Strict mode, JSON, Array methods |
| 2015 | ES6 (ES2015) | let/const, arrow functions, classes, modules, promises |
| 2016+ | ES7+ (ES2016+) | Exponentiation, async/await, object spread, etc. |
Why Version Matters
- Older browsers may not support the latest features.
- Transpilers (like Babel) help use new features in old environments.
Summary
Stay up to date with JavaScript versions to use modern features and write better code. Check browser compatibility before using new syntax.