How to merge two arrays in JavaScript

In this Article we will go through how to merge two arrays only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

// Merge but don't remove the duplications
const merge = (a, b) => a.concat(b);

const merge = (a, b) => [...a, ...b];

// Merge and remove the duplications
const merge = [...new Set(a.concat(b))];

const merge = [...new Set([...a, ...b])];