Trying To Shuffle Multiple Arrays In Javascript But In The Same Way?

I want to randomly shuffle these two arrays in the same function var array1 = [1,2,3,4,5]; var array2 = [6,7,8,9,10]; So that it returns each array randomly shuffled such as 4,2,3

Solution 1:

Added shuffle method to Array.prototype for easy access - returns a modified array keeping the original unchanged.

Array.prototype.shuffle = function() {
  var rIndex, temp,
    input = this.slice(0),
    cnt = this.length;

  while (cnt) {
    rIndex = Math.floor(Math.random() * cnt);
    temp = input[cnt - 1];
    input[cnt - 1] = input[rIndex];
    input[rIndex] = temp;
    cnt--;
  }

  return input;
}

var array1 = [1, 2, 3, 4, 5];
var array2 = [6, 7, 8, 9, 10];

document.getElementById('shuffle-btn').onclick = function(){
  document.getElementById('output').innerHTML = [array1.shuffle(), array2.shuffle()].join('\n');
}

<buttonid="shuffle-btn">Shuffle</button><preid="output"></pre>