Question

How to concatenate three arrays in JavaScript

Answer 1

var arr_n1 = [1, 2, 3],
    arr_n2 = [4, 5, 6],
    arr_n3 = [7, 8, 9];

var arr = arr_n1.concat(arr_n2, arr_n3);

for (i = 0; i < arr.length; i++)
  document.write("arr[" + i + "] = " + arr[i] + "<br />"); 

/*
run:  

arr[0] = 1
arr[1] = 2
arr[2] = 3
arr[3] = 4
arr[4] = 5
arr[5] = 6
arr[6] = 7
arr[7] = 8
arr[8] = 9

*/

 

70+ SQL courses for beginners and professionals