How to swap the array elements in JavaScript

In this tutorial, we are going to learn about two different ways to swap the two elements of an array in JavaScript.

Consider, we have an array like this.

const arr = [10, 20, 30, 40];

Now, we want to swap the element 20 with element 40.

Using the temporary variable

To swap the array elements, first we need to initialize a temp (temporary) variable and assign the element 20 to it, then update the element 20 index with element 40 index and we assign the temp variable to element 20 index.

Here is an example:

const arr = [10, 20 ,30, 40];

const temp = arr[1];
arr[1] = arr[3];
arr[3] = temp;

console.log(arr); // [10, 40, 30, 20]

Using the es6 destructuring assignment

Similarly, we can also use the es6 destructuring assignment syntax to swap elements in an array like this.

const arr = [10, 20 ,30, 40];

[arr[1], arr[3]] = [arr[3], arr[1]];

console.log(arr); // [10, 40, 30, 20]