JavaScript Version Numbers

Old ECMAScript versions was named by numbers: ES5 and ES6.

From 2016, versions are named by year: ES2016, 2018, 2020 ...

New Features in ECMAScript 2016

This chapter introduces the new features in ECMAScript 2016:

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

Browser Support

ES 2016 is fully supported in all modern browsers since March 2017:

Chrome 52	Edge 15	Firefox 52	Safari 10.1	Opera 39
Jul 2016	Apr 2017	Mar 2017	May 2017	Aug 2016

ES 2016 is not supported in Internet Explorer.

Exponentiation Operator

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

Example

let x = 5;
let z = x ** 2;

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

Example

let x = 5;
let z = Math.pow(x,2);

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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;

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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

JavaScript Array includes()

ECMAScript 2016 introduced Array.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");

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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