Collider2D instance passed into an if condition

Hello, I found on internet a script that passes a collider instance into the “()” brackets of an if condition.
Can you please explain me what does this mean?
Which kind of control does the script do in this way? Thank you

Collider2D coll = new Collider2D();
if (coll) 
{
			Debug.Log("what does it mean coll instance put into the if statement condition ?");
}

If I understand your question, I think you’re asking “What does if(coll) mean?”

If that’s the question here, all it says is

“If coll not null”

If coll exists (in this case it does, because you initialized the variable with a new collider) then the if statement is true, then the code inside the if statement will run.

However if coll was null (for example, no collider found) then the if statement if false, and the code inside the statement will not run.