Workshop › Tetris-style Blocks › Step 12 of 32

Move with the arrows

What we are doing

The arrow keys move the piece left, right and down. Each is tryMove with a different (dx, dy). Afterwards we redraw, because nothing redraws the screen by itself yet.

```js
document.addEventListener('keydown', (event) => {
  if (event.key === 'ArrowLeft') tryMove(-1, 0)
  if (event.key === 'ArrowRight') tryMove(1, 0)
  if (event.key === 'ArrowDown') tryMove(0, 1)
  draw()
})
```

What it means

• addEventListener('keydown', ...) runs the function every time a key goes down; event.key is its name.
• Each if checks one arrow and tries the matching move.
• draw() shows the result.

Your turn

Write the listener above function drawCell(, then Run, click the game and use the arrows.

Skills: Keyboard and mouse input

← Try, then move Turn a matrix →

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