by Sai gowtham

How to use es6 Spread(...) operator JavaScript

How to use es6  Spread(...) operator JavaScript

Spread syntax(… three dots)

The spread syntax allows us to expand the arrays or strings where zero or more arguments are needed for the function calls or array literals or object literals.

Let’s see in practice

Combine arrays

const fruits = ['apples', 'apricots', 'avocados'];
const veg = ['broccoli','corn','cucumber'];

const vegplusfruits = [...fruits,...veg];

console.log(vegplusfruits);

// ['apples', 'apricots', 'avocados','broccoli','corn','cucumber']

In the above code, we combined two arrays into a single array by using the spread operator.

Function calls

We can use spread operator to pass the array of numbers as an function arguments.

Here is an example:

function sum (a,b,c,d,e,f,g,h){
   return a+b+c+d+e+f+g+h;
}

const numbers =  [1,2,3,4,5,6,7,8];

console.log(sum(...numbers));

//output -> 36

Copying Objects

const user1 = {
    id: 1,
    name: "king",
}

const users = {
    ...user1,
    id: 2,
    name: "pop"
}

console.log(users);

// {id: 1, name: "king", id:2, name: "pop"}

Splitting the Strings

We can also use spread operator to split the single string into an array of strings.

const name = "opera";
const array = [...name];

console.log(array);

// ["o", "p", "e", "r", "a"]

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