How to Get the Difference Between Two Arrays in Javascript?

When working with JavaScript, you may often come across situations where you need to find the difference between two arrays. Whether you want to compare two lists of items or filter out duplicate values, finding the difference between arrays can be a useful operation. In this article, we will explore multiple solutions to get the difference between two arrays in JavaScript.

1. Using the filter() method

The filter() method allows us to create a new array with elements that pass a certain condition. By using this method, we can easily find the difference between two arrays.

const array1 = [1, 2, 3, 4, 5];
const array2 = [3, 4, 5, 6, 7];

const difference = array1.filter(item => !array2.includes(item));

console.log(difference);

The above code snippet will output [1, 2], which represents the elements in array1 that are not present in array2.

2. Using the Set object

The Set object is a built-in JavaScript object that allows you to store unique values of any type. By converting the arrays into sets, we can easily find the difference using the set operations.

const array1 = [1, 2, 3, 4, 5];
const array2 = [3, 4, 5, 6, 7];

const set1 = new Set(array1);
const set2 = new Set(array2);

const difference = [...set1].filter(item => !set2.has(item));

console.log(difference);

The above code snippet will also output [1, 2], which represents the elements in array1 that are not present in array2.

3. Using the lodash library

If you prefer a more comprehensive solution, you can use the lodash library, which provides a wide range of utility functions for JavaScript. The difference() function from lodash can be used to find the difference between two arrays.

const _ = require('lodash');

const array1 = [1, 2, 3, 4, 5];
const array2 = [3, 4, 5, 6, 7];

const difference = _.difference(array1, array2);

console.log(difference);

The above code snippet will also output [1, 2], which represents the elements in array1 that are not present in array2. Make sure to install the lodash library before using this approach.

Now that you have learned multiple ways to get the difference between two arrays in JavaScript, you can choose the method that best suits your needs. Whether you prefer using built-in JavaScript methods or external libraries, these solutions will help you efficiently compare and filter arrays.