merge arrays without adding to end javascript 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: javascript concat two arrays

//ES6
const array3 = [...array1, ...array2];