Workshop › Blackjack › Step 3 of 22

Shuffle

What we are doing

A sorted deck is no game. The Fisher–Yates shuffle is the fair way: from the last card down, swap each card with a random card at or before it.

```js
// A new shuffled deck of 52 cards (Fisher–Yates).
  for (let i = deck.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1))
    ;[deck[i], deck[j]] = [deck[j], deck[i]]
  }
```

What it means

i goes from 51 down to 1; j is a random position from 0 to i.
[deck[i], deck[j]] = [deck[j], deck[i]] swaps two cards in one line.
The ; at the start stops JavaScript from gluing the [ line to the line before.

Your turn

Above newDeck, write the comment.
At the end of newDeck, write the shuffle loop.

Skills: Arrays and objects, Loops

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