Workshop › Lunar Lander › Step 11 of 31

Flying or not

What we are doing

The lander is either flying or already on the ground. A state variable says which, and update does nothing unless flying.

```js
let state // 'flying', 'landed' or 'crashed'

  state = 'flying'

  if (state !== 'flying') return
```

What it means

• reset starts every flight in the 'flying' state.
• !== means "is not equal"; return leaves update at once, so nothing moves.

Your turn

1. Under let gravity write let state with its comment.
2. In reset, under gravity = 0.025, write state = 'flying'.
3. In update, write the if as the first line, followed by an empty line.

Skills: Game states

← Around the sides Touching the ground →

All steps

1. Random hills
2. Draw the hills
3. A landing pad
4. The height at any x
5. The lander
6. Draw it around its own middle
7. Two feet
8. The game loop
9. Moon gravity
10. Around the sides
11. Flying or not
12. Touching the ground
13. Remember held keys
14. Tilt
15. The engine
16. A flickering flame
17. Fuel
18. Touch controls
19. Landing or crashing
20. Fly again
21. Landed or crashed?
22. Readouts
23. Levels
24. Score
25. Next level or new game
26. A narrower pad
27. A high score
28. Burst into pieces
29. Pieces fall and fade
30. Draw the wreck
31. Build it yourself: wind