Workshop › Tetris-style Blocks › Step 10 of 32

Blocks are in the way

What we are doing

Second part: a cell does not fit where the board already has a block. Rows above the top of the well count as empty, so a piece can stick out above the well for a moment.

```js
if (row >= 0 && board[row][col]) return false
```

What it means

• && means "and": only inside the well (row >= 0) do we look at the board, and a filled cell there means no fit.
• Because && stops at the first false part, board[row] is never read for a row above the well.

Your turn

In fits, under the walls line (if (col < 0 || ...), write the new line.

Skills: Collision detection

← Does it fit inside the well? Try, then move →

All steps

1. The well
2. The board as rows of numbers
3. Draw one cell
4. Draw the whole board
5. The number is the color
6. A piece is a small grid
7. A list of shapes
8. All seven pieces
9. Does it fit inside the well?
10. Blocks are in the way
11. Try, then move
12. Move with the arrows
13. Turn a matrix
14. Turn with Up
15. Wall kicks
16. Falling by itself
17. A random piece at the top
18. Land and lock
19. One function starts a game
20. When the pile reaches the top
21. Game Over on screen
22. Play again
23. Clear full rows
24. Points for lines
25. The side panel
26. Levels
27. Faster every level
28. A fair bag of pieces
29. The next piece
30. Drop it
31. The ghost piece
32. Build it yourself: hold a piece