ECMAScript Versions and Features
A brief outline of ECMAScript 5 onwards and feature releases
We'll cover the following
Introduction
Over the years, multiple ECMAScript versions have been released with various features. These features are outlined here to show the impact on JavaScript and the changes over the years.
ECMAScript 5
ECMAScript 5, released in 2009, is known as ES5 or ECMAScript 2009. Some features released in ES5 we already used in the course:
Array
methods released in ES5 are:Array.isArray()
Array.map()
Array.reduce()
Array.filter()
Array.forEach()
- JSON support via
JSON
object along with the following methods:JSON.parse()
JSON.stringify()
- Object support via
Object
object by introducing the following methods:Object.create()
Object.keys()
Object.getPrototypeof()
- New methods for
Date
object:Date.now()
Beyond these features, ES5 lets users use strict
mode, which creates restrictions to avoid errors. For instance, it does not allow undeclared variables. Before ES5, there were no such restrictions.
Get hands-on with 1200+ tech skills courses.