concatenate three array javascript code example

Example 1: js join two arrays

[1,2,3].concat([4,5,6])
// [1,2,3,4,5,6]

Example 2: concatenate multiple arrays javascript

const array1 = ['a', 'b', 'c'];
const array2 = ['d', 'e', 'f'];
const array3 = [...array1, ...array2];

console.log(array3);
// expected output: Array ["a", "b", "c", "d", "e", "f"]