How to concatenate an array in javaScirpt code example

Example 1: combine two arrays javascript

let arr1 = [0, 1, 2];
let arr2 = [3, 5, 7];
let primes = arr1.concat(arr2);

// > [0, 1, 2, 3, 5, 7]

Example 2: combine 2 arrays javascript

//ES6 using the spread operator
const itemsA = [ 'Lightsaber', 'Mockingjay pin', 'Box of chocolates' ];
const itemsB = [ 'Ghost trap', 'The One Ring', 'DeLorean' ]
const allItems = [ ...itemsA, ...itemsB ];