Workshop › Connect Four › Step 6 of 38

All 42 holes

What we are doing

One loop drew a row. A second loop around it, over the rows, draws every row: 6 × 7 = 42 holes. This is a nested loop.

```js
for (let row = 0; row < ROWS; row++) {
  for (let col = 0; col < COLS; col++) {
    const x = col * CELL + CELL / 2
    const y = TOP + row * CELL + CELL / 2
    disc(x, y, '#0f172a')
  }
}
```

What it means

• The outer loop goes through the rows 0 to 5; for each row, the inner loop goes through the columns 0 to 6.
• y now depends on the row: each row is one cell lower.

Your turn

Put a for loop over the rows around the column loop, and add row * CELL to y.

Skills: Loops

← A whole row The board in memory →

All steps

1. A dark background
2. A drawing function
3. The blue board
4. One hole
5. A whole row
6. All 42 holes
7. The board in memory
8. Discs in their colors
9. Draw every frame
10. Where does the disc land?
11. Play a column
12. Taking turns
13. Click to play
14. The next disc
15. Whose turn?
16. Playing with the keyboard
17. Keys 1 to 7
18. A disc on its way
19. Gravity
20. Watch it fall
21. Inside the board?
22. Walking along a line
23. Four in a row?
24. We have a winner
25. Circle the four
26. Who won?
27. A draw
28. Play again
29. Try a move and take it back
30. Win, or block
31. Don't help the player
32. Prefer the middle
33. The computer's turn
34. Only on your turn
35. You and the computer
36. Counting wins
37. Show the score
38. Build it yourself: the loser starts