Workshop › Breakout › Step 3 of 39

Keep a number inside limits

What we are doing

The paddle must never leave the screen. We write a small helper, clamp, that squeezes any number between a minimum and a maximum. We will use it again and again.

```js
function clamp(value, min, max) {
  return Math.max(min, Math.min(max, value))
}
```

What it means

• value, min, max are the parameters: the three numbers you pass in.
• Math.min(max, value) cuts off anything above max; Math.max(min, ...) lifts anything below min.
• return hands the result back to whoever called the function.

Your turn

Leave an empty line under let paddle = { x: 200 } and write clamp there.

Skills: Functions

← Draw again and again Follow the mouse →

All steps

1. The field and the paddle
2. Draw again and again
3. Keep a number inside limits
4. Follow the mouse
5. A canvas shown at another size
6. A ball with a velocity
7. Draw a round ball
8. Move the ball
9. Bounce off the side walls
10. Bounce off the ceiling
11. The open floor
12. Bounce off the paddle
13. Aim with the paddle
14. A row of bricks
15. Draw the bricks
16. A whole wall: a loop inside a loop
17. A color for every row
18. Circle meets box
19. Break a brick
20. Hitting the side of a brick
21. Wait on the paddle
22. Ride along with the paddle
23. Launch the ball
24. Click or press Space
25. Remember which keys are held
26. Steer with the arrow keys
27. Three lives
28. Lives and a hint on screen
29. Game over
30. Keep score
31. Show the score
32. Win the game
33. One function for a new game
34. Play again
35. A burst of particles
36. Break into sparks
37. Move, fall and disappear
38. Fade out
39. Build it yourself: tough bricks