Can't assign to property "jumpHeight" on true: not an objecterrorInfo.stack?

Cocos Creator
#1

I decided to test the standard physics and collision in the engine. I used an example:

start () {
        this.rigidbody = this.node.getComponent(RigidBody2D);

        this.collider = this.node.getComponent(BoxCollider2D);
        if( this.collider ) {
            this.collider.on(Contact2DType.BEGIN_CONTACT, this.onBeginContact, this);
        }
    }
    onBeginContact( selfCollider: BoxCollider2D, otherCollider: BoxCollider2D, contact: IPhysics2DContact | null ) {
        
        if( otherCollider.name == "star<BoxCollider2D>" ){
            otherCollider.node.getComponent("Star").destroyStar();
            this.score++;
            this.scoreLabel.string = "Score: " + this.score;
        }

    }

Here’s my code:

    start() {
        this.rigidbody = this.node.getComponent(RigidBody2D);
        this.collider = this.node.getComponent(Collider2D);
        if (this.collider) {
            this.collider.on(Contact2DType.BEGIN_CONTACT, this.onBeginContact, true);
        }
        this.node.getComponent(Animation).play("idle");
    }
    onBeginContact(selfCollider: BoxCollider2D, otherCollider: BoxCollider2D, contact: IPhysics2DContact | null) {
        if (otherCollider.name == "Floor<BoxCollider2D>") {
            this.jumpHeight = 0;
        }
    }

My code gives this error:
can't assign to property "jumpHeight" on true: not an objecterrorInfo.stack ?
How can I correct this error?

#2

hi,bro!
pay attention to the last parameter of collider.on.
it is the thisArg of the callback function.
in your code context, it should be this.

#3

Thank you for your reply.

#4

Sorry, I forgot to answer this question. I was able to solve the problem. I took the variable outside of the class, that helped.