javascript union two arrays code example

Example 1: javascript array concat spread operator

const arr1 = [1,2,3]
const arr2 = [4,5,6]
const arr3 = [...arr1, ...arr2] //arr3 ==> [1,2,3,4,5,6]

Example 2: js merge 2 lists

var array1 = ["Vijendra", "Singh"];
var array2 = ["Singh", "Shakya"];

console.log(array1.concat(array2));
// output: ["Vijendra", "Singh", "Singh", "Shakya"]