OnCollisionEnter2D and OnTriggerEnter2D in Unity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to detect a collision with another object.

Unity

void [1](Collision2D collision) {
    Debug.Log("Collision detected with " + collision.gameObject.name);
}

Drag options to blanks, or click blank then click option'

AUpdate

BOnTriggerEnter2D

CStart

DOnCollisionEnter2D

Attempts:

3 left

💡 Hint

Common Mistakes

Using OnTriggerEnter2D instead of OnCollisionEnter2D for collision detection.

Using Start or Update methods which are unrelated.

The method OnCollisionEnter2D is called when this object collides with another collider and both have Rigidbody2D components.

2fill in blank

medium

Complete the code to detect when another object enters a trigger collider.

Unity

void [1](Collider2D other) {
    Debug.Log("Trigger entered by " + other.gameObject.name);
}

Drag options to blanks, or click blank then click option'

AOnCollisionExit2D

BOnTriggerExit2D

COnTriggerEnter2D

DOnCollisionEnter2D

Attempts:

3 left

💡 Hint

Common Mistakes

Using OnCollisionEnter2D instead of OnTriggerEnter2D for triggers.

Confusing enter and exit methods.

The method OnTriggerEnter2D is called when another collider enters a trigger collider attached to this object.

3fill in blank

hard

Fix the error in the method signature to detect collision correctly.

Unity

private void [1](Collision2D collision) {
    Debug.Log("Hit " + collision.gameObject.name);
}

Drag options to blanks, or click blank then click option'

AOnCollisionEnter2D

BOnTriggerEnter2D

COnTriggerEnter

DOnCollisionEnter

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3D collision methods with 2D physics.

Mismatching method name and parameter type.

For 2D physics, the method must be OnCollisionEnter2D and use Collision2D as parameter.

4fill in blank

hard

Fill both blanks to create a method that logs when an object exits a trigger.

Unity

void [1](Collider2D [2]) {
    Debug.Log("Trigger exited by " + [2].gameObject.name);
}

Drag options to blanks, or click blank then click option'

AOnTriggerExit2D

BOnCollisionExit2D

Cother

Dcollision

Attempts:

3 left

💡 Hint

Common Mistakes

Using OnCollisionExit2D instead of OnTriggerExit2D.

Using 'collision' as parameter name for trigger methods.

The method OnTriggerExit2D detects when a collider leaves a trigger. The parameter is usually named other to represent the other collider.

5fill in blank

hard

Fill all three blanks to create a method that detects collision and logs the tag of the other object if it is 'Enemy'.

Unity

void [1](Collision2D [2]) {
    if ([3].gameObject.tag == "Enemy") {
        Debug.Log("Collided with Enemy");
    }
}

Drag options to blanks, or click blank then click option'

AOnCollisionEnter2D

Bcollision

Cother

DOnTriggerEnter2D

Attempts:

3 left

💡 Hint

Common Mistakes

Using OnTriggerEnter2D instead of OnCollisionEnter2D for collisions.

Using wrong parameter names or inconsistent names.

The method OnCollisionEnter2D detects collisions. The parameter is often named collision. We check the tag of the colliding object using this parameter.