Workshop › Flappy-style Bird › Step 8 of 30

A flap

What we are doing

A flap does not push the bird up by some pixels: it sets its velocity to a fixed upward speed, -8. Gravity does the rest.

```js
const FLAP = -8 // the bird's speed right after a flap (negative = up)

function flap() {
  bird.vy = FLAP
}
```

What it means

• FLAP is negative because y grows downwards: going up means y gets smaller.
• bird.vy = FLAP sets the speed. With += a flap while falling fast would barely help, and two flaps would launch the bird into space. Setting it makes every flap feel the same.

Your turn

1. Under the GRAVITY line, write the FLAP line.
2. Under the bird line, leave an empty line and write flap. Press Run.

Skills: Velocity and gravity

← Gravity Space, Up arrow or a tap →

All steps

1. Get the canvas and the pen
2. Paint the sky
3. Draw the bird
4. A function that draws
5. A function that moves
6. The game loop
7. Gravity
8. A flap
9. Space, Up arrow or a tap
10. Wait for the first flap
11. The ground and the sky
12. Tell the player
13. A pipe as data
14. Draw the pipes
15. The world moves, not the bird
16. A new pipe at a random height
17. A pipe every 90 frames
18. Remove the pipes you passed
19. Is the bird level with a pipe?
20. Through the opening
21. Score each pipe once
22. Show the score
23. A function for a fresh start
24. Try again
25. One place where the game ends
26. Remember the best score
27. Show the best score
28. The same speed on every screen
29. No catching up after a pause
30. Build it yourself: a medal