Workshop › Snake › Step 21 of 28

Crash into yourself

What we are doing

Running into your own body ends the game too. The tail is left out of the check, because it moves away this turn.

```js
const hitSelf = snake.slice(0, -1).some((part) => part.x === head.x && part.y === head.y)
if (hitWall || hitSelf) {
```

What it means

• snake.slice(0, -1) is a copy of the snake without its last part (the tail).
• .some(...) is true if any of those parts is on the new head's cell.
• The game ends on a wall or on yourself.

Your turn

Under hitWall write hitSelf, and change if (hitWall) to if (hitWall || hitSelf).

Skills: Collision detection, Arrays and objects

← Crash into the walls The game over message →

All steps

1. Find the canvas
2. Get the pen
3. Paint the board
4. Think in cells
5. Keep the position in a variable
6. A function that draws
7. A function that moves
8. The game loop
9. Slow it down
10. A direction to move in
11. Steer with the arrow keys
12. A body made of a list
13. Move the whole body
14. Pick a spot for the food
15. Draw the food
16. Eat and grow
17. Never put food on the snake
18. A table of turns
19. No U-turns
20. Crash into the walls
21. Crash into yourself
22. The game over message
23. Show the score
24. One function that starts a game
25. Play again with Space
26. Remember the best score
27. Speed up as you grow
28. Build it yourself: through the walls