How to combine two arrays in JavaScript

In this tutorial, we are going to learn about how to combine two or more arrays in JavaScript with the help of examples.

In JavaScript, there are manyways to combine arrays let’s learn the most commonly used methods for combining the arrays.

Using Spread operator

To combine the two arrays into a single array, we can use the es6 spread(…) operator in JavaScript.

Here is an example:

const num1  = [1, 2];
const num2  = [3, 4];

console.log([...num1,...num2]);

Output:

[1, 2, 3, 4]

Note: The spread(…) operator unpacks the iterables (such as sets, arrays, objects, etc) into a individual elements.

Using Array.Concat( ) method

We can use the built-in Array.concat() method to combine arrays in JavaScript.

The Array.concat() method takes the one or more arrays as an argument and returns the new array by combining it. It doesn’t mutates the existing arrays.

Here is an example:

const num1  = [1, 2];
const num2 =  [3, 4];

const result = num1.concat(num2);
console.log(result);

Merging three arrays

const num1 = [1, 2];
const num2 = [3, 4];
const num3 = [5, 6];

console.log(num1.concat(num2,num3));

Output:

[1, 2, 3, 4, 5, 6]