Workshop › Conway's Game of Life › Step 21 of 32

Clear and shuffle

What we are doing

Two more buttons: 'Clear' empties and stops the world (C), 'Random' throws in a new soup (R).

```js
function clear() {
  grid = emptyGrid()
  generation = 0
  playing = false
}

  } else if (button === 'Random') randomize()
  else if (button === 'Clear') clear()
}

  const keys = { ' ': 'Play', n: 'Step', r: 'Random', c: 'Clear' }
```

What it means

• clear puts an empty grid in place, sets the generation to 0 and stops the world.
• press gets two more cases, and the key table two more keys.

Your turn

1. Under randomize, after an empty line, write clear.
2. In press, change } after step() to } else if (button === 'Random') randomize() and add the 'Clear' line.
3. Add r and c to the key table.

Skills: Keyboard and mouse input, Game states

← Space to play, N to step Where is the pointer? →

All steps

1. The board
2. Measure the grid
3. One living cell
4. A function that draws
5. The world in memory
6. Draw every living cell
7. A random soup
8. Count the neighbours
9. Four rules
10. Draw again and again
11. Next generation with N
12. Count the generations
13. Show the generation
14. A world without edges
15. Count the living
16. A generation every few frames
17. Let it live
18. Running or not
19. One place for the buttons
20. Space to play, N to step
21. Clear and shuffle
22. Where is the pointer?
23. Which cell?
24. Click a cell
25. Paint or erase?
26. Drag to paint
27. Patterns from text
28. The glider gun
29. Fire the gun
30. Buttons on the screen
31. Tap the buttons
32. Build it yourself: a world at rest