Spread Operator in JavaScript

Paramjit Singh
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Introduction

The evolution of JavaScript to the ES6 version has brought a whole array of new tools and utilities. One such new feature is the spread operator.

Spread operator

Spread operator allows an inerrable to expand in places where 0+ arguments are expected. It is mostly used in the variable array where there is more than 1 value is expected. JavaScript ECMAScript 6 introduced the spread operator. The operator’s shape is three consecutive dots and is written as:

Syntax

var variablename = [...value];

Examples are given below.

const nambers = [1, 2, 3 ,4 ,5 ,6 ,7 ,8 ,9 ,10];
console.log (...nambers);
Spread in function calls
1. function Subtract (x, y, z) {
2. return x * y * z;
3. }
4. const Subnumbers = [5,6,7,8];
5. console.log (Subtract (...Subnumbers));

Spread in array literals
1. var one = ['Ravi', 'Vicky'];
2. var two = ['mohit', ...one, 'and', 'Jasi'];
3. console.log (two);
A better way to concatenate arrays.
1. var First = [0, 1, 2];
2. var Second = [3, 4, 5];
3. var third = [...First, ... Second];
4. console.log (third);
Spread in object literals
1. var Emp1 = {Name:'baljit', Address: 'New York', Salary:'5000'};
2. var Emp2 = {Age: 32, Mobile: 98729648};
3. var mergedEmp = {...Emp1, …Emp2};
4. console.log (mergedEmp);
Spread in with Functions
1. const numbers = [5, 6, 8, 9, 11, 999];
2. Math.max (...numbers)
Spread in with Array
1. const item = ['This', 'is', 'a', 'Java Script'];
2. console.log(item)
3. console.log (...item)