ES2016

The ES2016 language specification was rolled out without much fanfare. It was probably a quiet release because it only has a couple new minor features.

ES2016 Features:

• Array.proptype.includes
• Exponentiation Operator

Array.proptype.includes

A new method was introduced to Array that determines whether an item is within the array. The new function has two signatures; one signature for searching the entire array for an item and another for searching the array starting at a specified index.

The following example inspects the entire array for an item.

const array = [1, 2, 3];
array.includes(3);  // true
array.includes(4);  // false

The following example inspects the array for an item, but starting at a specified index.

const array = [1, 2, 3];
const fromIndex = 2;
array.includes(3, fromIndex);  // true
array.includes(1, fromIndex);  // false

Exponentiation Operator

The exponentiation operator (**) was introduced as syntactic sugar for Math.pow(base, exponent).

The following is a simple example of calculating the three squared;

const x = 3 ** 2;
console.log(x);  // 9

It is possible to update a variable using the exponentation operator.

let x = 3;
x **= 2;
console.log(x); // 9

Summary

While the new features in ES2016 aren’t as game changing as the features provided by ES2015, it is still reassuring to see the EcmaScript specification updated on a regular schedule.

Most major browsers provide support for Array.prototype.includes except for Internet Explorer and few browsers support the new exponential operators. If these features are important to you as a developer, try running them through a transpiler like Babel.