This post is part of a Phaser series. Click here to see the first post of the series.

You can detect a collision between physics-enabled items.

Phaser offers us 2 handy methods, to start with.

We have collider and overlap. Both let us detect when objects get near each other, but with a difference: collider automatically makes objects bounce when they meet. overlap lets objects overlap with each other.

This is how we add a collider:

const collisionHappened = (dog, cat) => {
  projectile.destroy()
}

this.physics.add.collider(dogs, cats, collisionHappened, null, this)

and this is how we add an overlap:

const overlapHappened = (dog, cat) => {
  projectile.destroy()
}

this.physics.add.overlap(dogs, cats, collisionHappened, null, this)

You can also set screen boundaries so physics objects will not disappear when they reach the end of the screen.

Call the setCollideWorldBounds() on the object, and pass it the true value:

const dog = this.physics.add.sprite(20, 20, 'dog')
dog.setCollideWorldBounds(true)

If you also want it to bounce when it reaches the screen limit, call

dog.setBounce(1)

The number you pass will determine how fast it will bounce back. Try setting 0.5 or 1.5 and you’ll see it bouncing with less or more energy.

Lessons in this unit:

0:	Introduction
1:	Setting up a project to build a JavaScript game with Phaser
2:	Phaser: The Canvas
3:	Phaser: Scenes
4:	Phaser: Multiple scenes
5:	Phaser: The game loop
6:	Phaser: Adding images
7:	Phaser: Sprites
8:	Phaser: GameObjects
9:	Phaser: Animations
10:	Phaser: Keyboard events
11:	Phaser: Mouse input
12:	Phaser: Physics
13:	▶︎ Phaser: collisions and screen boundaries
14:	Phaser: Playing sounds
15:	How to create a platformer game with Phaser.js