Difference between two arrays in JavaScript

In this tutorial, we are going to learn about how to get a difference between two arrays in JavaScript with the help of examples.

Consider we have two arrays like this.

const arr1 = [1,2,3,4];
const arr2 = [1,2,4,5];

The difference between the above two arrays is [3,5].

Let’s write the solution in JavaScript with the help of es6 filter() and includes() method.

function getDifference(arr1,arr2){
             return  arr1
                   // filtering difference in first array with second array
                 .filter(x => !arr2.includes(x))
                    // filtering difference in second array with first array
                 .concat(arr2.filter(x => !arr1.includes(x)));
}

const arr1 = [1,2,3,4];
const arr2 = [1,2,4,5];

getDifference(arr1,arr2); // [3,5]

Explanation

In the above code, we have first filtered the difference in the first array with the second array using filter and includes method then we chained with the concat method.

Inside the concat() method we have filtered the difference in the second array with the first array.