shiljopaulson/es7_samples

Features of ES7/ECMA 2016

Features of ES7/ECMA 2016

By mid of 2016 the ECMAScript 2016 got approved. In this post we are going to discuss about the new features included in ES7 aka ECMA 2016. As per ECMA International the standards organisation have agreed to have yearly periodical release of new standards/features for ECMA Script. This helps browsers vendors to align and manage things. Insted of having one big list of feature sets which we had for ES6/ECMA 2015. So lets see what are the new features introduced in ES7

Exponentiation Operator

Exponentiation is a mathematical operation, written as bn, involving two numbers, the base b and the exponent n. When n is a positive integer, exponentiation corresponds to repeated multiplication of the base: that is, bn is the product of multiplying n bases - Wikipedia In short in Math.pow(n,n) is new form the syntax is

Syntax

base ** exponent

lets see the code snippet to know more

console.log(3 * 3 * 3);//27
console.log(Math.pow(3, 3));//27
 
// Exponentiation Operator ** introduced in ES 2016 aka ES7
console.log(3 ** 3);//27
 
var num = 3;
//short hand form
num**=3;
console.log(num);//27
 
// Funny cases
console.log(3 ** 0);//1 
console.log(NaN ** 0);//1 
console.log(Infinity ** 0);//1 
 
console.log(3 ** NaN);//NaN 
console.log(NaN ** NaN);//NaN 
console.log(Infinity ** NaN);//NaN 

includes() in Array

The includes() method determines whether an array contains a specific element, returning either true or false.

Array already has a method indexOf() which returns type of number. If -1 then object is not found else item is found from the array

Syntax

arrayVar.includes(searchElement)

arrayVar.includes(searchElement, fromIndex)

searchElement: The element to search for.

fromIndex (optional): The position (index position) in this array at which to begin searching for searchElement. Default value is 0 (zero)

lets see the code snippet to know more

var numList = new Array(44, 22, 55, 11, 55);
// or var numList = [44, 22, 55, 11];
 
console.log(numList.indexOf(55));//2
console.log(numList.indexOf(32));//-1
 
// includes() introduced in ES 2016 aka ES7
console.log(numList.includes(55));//true
console.log(numList.includes(32));//false
 
console.log(numList.includes(55, 3));//true
 
console.log(numList.includes(22));//true
console.log(numList.includes(22, 2));//false

The snippet shared here may not work in some browsers so you might need to transpile it to ES5