need help with C# component reference

Questions & Answers
1

I have several copies of a box prefab that has the following components:
“BoxColider2D”,
“RigidBody2D”,
“Sprite Renderer” & a custom C# script called “BoxDestruction”.

I also have a “Danger Zone” object which has a BoxCollider2D with isTrigger enabled. I want to destroy boxes that are inside the “Danger Zone” trigger at random intervals (when the destroyBox bool is true).

I am using the following code on the “Dander Zone” trigger to try and call the public DestroyBox() function in the “BoxDestrction” script of the box which is inside the trigger. I am getting a NullReferenceException: Object reference not set to an instance of an object, but i cannot tell why? i thought that starting from “other” would give me the instance of the object i am after?

void OnTriggerStay2D (Collider2D other)
{
	if(other.tag == "Destructible")
	{
		if(destroyBox)
			other.gameObject.GetComponent<BoxDestruction>().DestroyBox(); 
	}
}

Can anyone tell me what i am doing wrong when trying to reference this? i would really appreciate an explanation, as i can’t see where i am going wrong…

Thanks in advance!

2

Assuming that the DestroyBox takes a GameObject parameter you could do it this way.

Declare the BoxDestruction variable at the top of your script.

BoxDestruction boxDestruction;

Make the reference in the Start function.

void Start() {
     boxDestruction = GetComponent<BoxDestruction>();
}

Now call the function.

void OnTriggerStay2D (Collider2D other)
{
    if(other.tag == "Destructible")
    {
       if(destroyBox)
         boxDestruction.DestroyBox(other.gameObject); 
    }
}