ECMAScript 2016

JavaScript Version Numbers

Old JS versions are named by numbers: ES5 (2009) and ES6 (2015).

From 2016, versions are named by year: ECMAScript 2016, 2017, 2018, 2019, ...

This chapter introduces the new features in ECMAScript 2016:

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

let x = 5;
let z = x ** 2;

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

let x = 5;
let z = Math.pow(x,2);

exponentiation assignment**=

let x = 5;
x **= 2;

The Exponentiation Operator is supported in all modern browsers since March 2017:


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

ECMAScript 2016 introduced Array.includes to arrays.

This allows us to check if an element is present in an array:

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

fruits.includes("Mango");

Array.includes is supported in all modern browsers since August 2016:


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