how to add the contents of two arrays and write to another code example

Example 1: javascript push all elements of array to another array

var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);

Example 2: push another array to array typescript

var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);