access variable

hello,
The Player object has a public float named "size", and the Circle object has a public float named "size".I want to be able to increase size from the Circle, but I can't. The code is as follows:
The code is as follows:
Collision2D collisionEnter2D(void)
{i
"Player" if (coll.gameObject.name)
{
The size of this.GetComponent*playerMovement>() is equal to 1;
}
}
I get a nullreferenceexception error whenever I run this code. Since I have no idea what code is, I would appreciate a brief explanation of Unity and C#.

 

This should help https://forum.unity.com/threads/help-in-assecing-variable.1187497/