Tutorials References Menu

JS Tutorial

JS HOME JS Introduction JS Where To JS Output JS Statements JS Syntax JS Comments JS Variables JS Let JS Const JS Operators JS Arithmetic JS Assignment JS Data Types JS Functions JS Objects JS Events JS Strings JS String Methods JS String Search JS Numbers JS Number Methods JS Arrays JS Array Methods JS Array Sort JS Array Iteration JS Array Const JS Dates JS Date Formats JS Date Get Methods JS Date Set Methods JS Math JS Random JS Booleans JS Comparisons JS Conditions JS Switch JS Loop For JS Loop For In JS Loop For Of JS Loop While JS Break JS Typeof JS Type Conversion JS Bitwise JS RegExp JS Errors JS Scope JS Hoisting JS Strict Mode JS this Keyword JS Arrow Function JS Classes JS JSON JS Debugging JS Style Guide JS Best Practices JS Mistakes JS Performance JS Reserved Words

JS Objects

Object Definitions Object Properties Object Methods Object Display Object Accessors Object Constructors Object Prototypes Object Reference Object Map() Object Set()

JS Functions

Function Definitions Function Parameters Function Invocation Function Call Function Apply Function Closures

JS Classes

Class Intro Class Inheritance Class Static

JS Async

JS Callbacks JS Asynchronous JS Promises JS Async/Await

JS Versions

JS Versions JS 2009 (ES5) JS 2015 (ES6) JS 2016 JS 2017 JS 2018 JS IE / Edge JS History

JS HTML DOM

DOM Intro DOM Methods DOM Document DOM Elements DOM HTML DOM Forms DOM CSS DOM Animations DOM Events DOM Event Listener DOM Navigation DOM Nodes DOM Collections DOM Node Lists

JS Browser BOM

JS Window JS Screen JS Location JS History JS Navigator JS Popup Alert JS Timing JS Cookies

JS Web APIs

Web API Intro Web Forms API Web History API Web Storage API Web Worker API Web Fetch API Web Geolocation API

JS AJAX

AJAX Intro AJAX XMLHttp AJAX Request AJAX Response AJAX XML File AJAX PHP AJAX ASP AJAX Database AJAX Applications AJAX Examples

JS JSON

JSON Intro JSON Syntax JSON vs XML JSON Data Types JSON Parse JSON Stringify JSON Objects JSON Arrays JSON Server JSON PHP JSON HTML JSON JSONP

JS vs jQuery

jQuery Selectors jQuery HTML jQuery CSS jQuery DOM

JS Examples

JS Examples JS HTML DOM JS HTML Input JS HTML Objects JS HTML Events JS Browser JS Editor

JS References

JavaScript Objects HTML DOM Objects


ECMAScript 2016

The JavaScript naming convention started with ES1, ES2, ES3, ES5 and ES6.

But, ECMAScript 2016 and 2017 was not called ES7 and ES8.

Since 2016 new versions are named by year (ECMAScript 2016 / 2017 / 2018).

New Features in ECMAScript 2016

This chapter introduces the new features in ECMAScript 2016:

  • JavaScript Exponentiation (**)
  • JavaScript Exponentiation assignment (**=)
  • JavaScript Array.prototype.includes

Exponentiation Operator

The exponentiation operator (**) raises the first operand to the power of the second operand.

Example

let x = 5;
let z = x ** 2;          // result is 25
Try it Yourself »

x ** y produces the same result as Math.pow(x, y):

Example

let x = 5;
let z = Math.pow(x,2);   // result is 25
Try it Yourself »

Exponentiation Assignment

The exponentiation assignment operator (**=) raises the value of a variable to the power of the right operand.

Example

let x = 5;
x **= 2; // result 25
Try it Yourself »

Chrome 52 and Edge 14 was the first browsers to fully support the Exponentiation Operator:

Chrome 52 Edge 14 Firefox 52 Safari 10.1 Opera 39
Jul 2016 Aug 2016 Mar 2017 Mar 2017 Aug 2016


JavaScript Array.includes()

ECMAScript 2016 introduced Array.prototype.includes to arrays. This allows us to check if an element is present in an array:

Example

const fruits = ["Banana", "Orange", "Apple", "Mango"];

fruits.includes("Mango"); // is true
Try it Yourself »

All modern browsers support Array.prototype.includes:

Chrome 47 Edge 14 Firefox 43 Safari 9 Opera 34
Des 2015 Aug 2016 Des 2015 Oct 2015 Des 2015