Get the intersection of two arrays in JavaScript

In this tutorial, we are going to learn about how to get the intersection of two array in JavaScript with the help of examples.

Intersection means the elements which are present in both array 1 and array 2.

Consider, we have the following two arrays in our code:

const arr1 = [4, 5, 6, 7];
const arr2 = [4, 6, 1, 3];

Now, we need to get the elements which are in intersection of both arrays.

Using filter() and includes()

To get the intersection of two arrays, we can use the combination of built-in filter() method and includes() method in JavaScript.

Here is an example, that returns the intersection of arr1 and arr2:

const arr1 = [4, 5, 6, 7];
const arr2 = [4, 6, 1, 3];

const intersection = arr1.filter(val=>arr2.includes(val));
console.log(intersection);

Output:

[4, 6]

Similarly, we can also find the intersection of two array in JavaScript like this.

const arr1 = [4, 5, 6, 7];
const arr2 = [4, 6, 1, 3];

const intersection = arr1.filter(val=>arr2.indexOf(val)<-1);
console.log(intersection); // [4,6]