JavaScript Versions
JavaScript Basics

JavaScript Versions

JavaScript, created by Brendan Eich in 1995, was standardized as ECMAScript in 1997. This standardization helps ensure compatibility across different web browsers. Here's an overview of the major milestones in ECMAScript's development:

ECMAScript Editions Overview

  • ES1 (ECMAScript 1, 1997): This was the first official edition of the language.
  • ES2 (ECMAScript 2, 1998): Made only editorial changes to align with the ISO/IEC standard.
  • ES3 (ECMAScript 3, 1999): Introduced regular expressions, try/catch error handling, switch statements, and do-while loops.
  • ES4: This version was never released.
  • ES5 (ECMAScript 5, 2009): Introduced "strict mode," JSON parsing, and improved array manipulations (e.g., Array.isArray(), iteration methods). It also allowed trailing commas in object literals.
  • ES6 (ECMAScript 2015): Significant update that introduced let and const for block-scoped variables, default parameters, new array methods like Array.find(), and Array.findIndex().

Since 2016, ECMAScript versions are named by their release year:

  • ECMAScript 2016: Added the exponential operator (**) and Array.includes().
  • ECMAScript 2017: Introduced string padding, Object.entries(), Object.values(), async functions, and made allowances for trailing commas in function parameters.
  • ECMAScript 2018: Brought in rest/spread properties, asynchronous iteration, Promise.finally(), and additions to RegExp.
  • ECMAScript 2019: Included String.trimStart(), String.trimEnd(), Array.flat(), Object.fromEntries(), and optional catch binding.
  • ECMAScript 2020: Introduced the Nullish Coalescing Operator (??).

Browser Support for ECMAScript Versions

  • ES1 to ES6: Fully supported in all modern browsers.
  • ECMAScript 5 (2009): Supported from various versions across major browsers including Chrome from November 2012, Firefox from May 2013, and Internet Explorer from March 2011.
  • ECMAScript 2015 (ES6): Supported in Chrome from May 2016, Firefox from March 2017, and Safari from September 2016.
  • ECMAScript 2016: Began support in Chrome and Opera in mid-2016, and by Safari in early 2017.

This evolution shows JavaScript's dynamic growth and adaptation to developer needs over the years, driven by its versions and browser support updates.

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