Workshop › Klondike Solitaire › Step 7 of 40

Piles in one object

What we are doing

Klondike is a game of piles: the stock (face down) and the waste next to it, four foundations where each suit is built up from the ace, and seven tableau columns. We keep them all in one object, piles, each pile an array of cards. deal starts with the whole deck in the stock.

```js
let piles // stock, waste, f0..f3 (foundations) and t0..t6 (tableau): arrays of { rank, suit, up }

function deal() {
  const deck = newDeck()
  piles = { stock: [], waste: [] }
  for (let f = 0; f < 4; f++) piles['f' + f] = []
  piles.stock = deck
}

deal()
```

What it means

• let piles is empty until deal fills it.
• piles = { stock: [], waste: [] } makes an object with two empty piles.
• piles['f' + f] = [] adds a key made of text: 'f' + 0 is 'f0'. So the loop adds f0 to f3.
• piles.stock = deck: the shuffled deck becomes the stock.
• deal() above requestAnimationFrame(loop) deals once when the page loads.

Your turn

1. Under const CH = 78 leave an empty line and write let piles ... with its comment.
2. Under newDeck, leave an empty line and write deal.
3. Write deal() just above the last line, requestAnimationFrame(loop). Press Run.

Skills: Arrays and objects, Game states

← Shuffle Deal the seven columns →

All steps

1. The green table
2. Draw one card
3. The face of a card
4. Red and black
5. A deck of 52
6. Shuffle
7. Piles in one object
8. Deal the seven columns
9. A place for every pile
10. Put the piles on the table
11. Fan out the columns
12. Outlines for empty places
13. Turn over a card
14. Space turns a card
15. Go through the stock again
16. What is under the pointer?
17. Hitting a card in a column
18. Tap the stock
19. Rule 1: building a column
20. Rule 2: building a foundation
21. Move cards by the rules
22. Turn over the uncovered card
23. Find where a card goes
24. Pick up a card
25. Tap to move
26. A move counter
27. Count the moves
28. Where did you grab it?
29. Follow the pointer
30. Draw the held cards at the pointer
31. Drop it where you want
32. Drop a king into an empty column
33. A clock
34. Winning
35. You won!
36. A new game
37. The best time
38. Snapshots of the table
39. Undo
40. Build it yourself: finish by itself