Workshop › Missile Command-style Defense › Step 8 of 35

One missile a second

What we are doing

The attack comes in a wave of 20 missiles. A countdown in update launches one, waits 60 frames (about a second), launches the next.

```js
let toLaunch // enemy missiles still to come in this wave
let launchIn

  toLaunch = 20
  launchIn = 30

function update() {
  if (toLaunch > 0) {
    launchIn -= 1
    if (launchIn <= 0) {
      launch()
      toLaunch -= 1
      launchIn = 60
    }
  }
}

function loop() {
  update()
```

What it means

reset sets 20 missiles to launch, the first one after 30 frames.
Each frame update counts launchIn down; at 0 it launches a missile, counts it off and waits 60 frames again.
The loop now calls update() before draw().

Your turn

Under let incoming ... write let toLaunch (with its comment) and let launchIn.
In reset, under incoming = [], write the two lines.
Write update just above function draw() {, with an empty line between.
In loop, call update() above draw().

Skills: The game loop

← Launch an enemy missile Missiles on their way →

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