Fisher-Yates Shuffle

The Fisher-Yates shuffle¹ is an algorithm for generating a random permutation of an array.

The algorithm is defined as follows:

-- To shuffle an array a of n elements (indices 0..n-1):
for i from n-1 down to 1 do
     j ← random integer such that 0 ≤ j ≤ i
     exchange a[j] and a[i]

The typescript implementation of the algorithm I normally use is:

1
shuffle(cards: any[]) {
2
  let m = cards.length;
3
  let t, i = 0;
4
  while(m) {
5
    i = Math.floor(Math.random() * m--);
6
    t = cards[m];
7
    cards[m] = cards[i];
8
    cards[i] = t;
9
  }
10
}