Workshop › Pinball › Step 14 of 42

Ready or playing

What we are doing

A ball waiting in the lane should stay put, and Space should launch only a waiting ball. A state variable says which of the two it is.

```js
let state // 'ready' (in the lane) or 'playing'

function newBall() {
  ball = { x: LANE_X, y: 570, vx: 0, vy: 0 }
  state = 'ready'
}

function update() {
  if (state === 'ready') return

function launch() {
  if (state !== 'ready') return
  ball.vy = -16
  state = 'playing'
}
```

What it means

newBall() makes every new ball 'ready'.
update returns at once while ready: no gravity, no move.
launch does nothing unless ready (!== means "is not"), and after launching the state is 'playing'.

Your turn

Under let ball write let state.
In newBall, under the ball = ... line, write state = 'ready'.
Make if (state === 'ready') return the first line of update.
In launch, add the first line and state = 'playing' at the end.

Skills: Game states

← Small steps and a speed limit The next ball →

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