Workshop › Tower Defense › Step 11 of 42

Here they come

What we are doing

Enemies arrive one at a time: spawnIn counts down every frame, and when it runs out a new enemy starts at d = 0 with 10 health, and the countdown starts again at 45. toSpawn says how many are still to come.

```js
let toSpawn // enemies still to come in this wave
let spawnIn // frames until the next one

  toSpawn = 30
  spawnIn = 0

function update() {
  if (toSpawn > 0) {
    spawnIn -= 1
    if (spawnIn <= 0) {
      enemies.push({ d: 0, hp: 10 })
      toSpawn -= 1
      spawnIn = 45
    }
  }
```

What it means

While enemies are left to come, spawnIn counts down.
At 0 or below, a new enemy joins the list, one fewer is left to come, and the next one is 45 frames away.
spawnIn starts at 0, so the first enemy comes at once.

Your turn

Under let enemies write let toSpawn and let spawnIn; in reset, under enemies = [], write toSpawn = 30 and spawnIn = 0.
At the top of update, write the spawning block and an empty line.

Skills: Game states, The game loop

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