README.md

ES2016 Or ES7

Table of Contents

No.	Feature
1	Array includes
2	Exponentiation Operator

ES2015/ES6 introduced a huge set of new features. But ECMAScript 2016 Or ES7 introduced only two new features:

1. Array.prototype.includes()

2. Exponentiation operator

3. Array Includes

   Prior to ES7, you have to use indexOf method and compare the result with '-1' to check whether an array element contains particular element or not.

    const array = [1,2,3,4,5,6];
    if(array.indexOf(5) > -1 ){
    console.log("Found an element");
    }

   Whereas in ES7, array.prototype.includes() method is introduced as a direct approach to determine whether an array includes a certain value among its entries or not.

   const array = [1,2,3,4,5,6];
   if(array.includes(5)){
   console.log("Found an element");
   }

In addition to this, Array.prototype.includes() handles NaN and Undefined values better than Array.prototype.indexOf() methods. i.e, If the array contains NaN and Undefined values then indexOf() does not return correct index while searching for NaN and Undefined.

let numbers = [1, 2, 3, 4, NaN, ,];
console.log(numbers.indexOf(NaN)); // -1
console.log(numbers.indexOf(undefined)); // -1

On the otherhand, includes method is able to find these elements

  let numbers = [1, 2, 3, 4, NaN, ,];
  console.log(numbers.includes(NaN)); // true
  console.log(numbers.includes(undefined)); // true

2. Exponentiation Operator

   The older versions of javascript uses Math.pow function to find the exponentiation of given numbers. ECMAScript 2016 introduced the exponentiation operator, **(similar to other languages such as Python or F#) to calculate the power computation in a clear representation using infix notation.

   //Prior ES7
   const cube = x => Math.pow(x, 3);
   console.log(cube(3)); // 27
   
   //Using ES7
   const cube1 = x => x ** 3;
   console.log(cube1(3)); // 27