GetComponent on null references

[crystal prism]

when you do playerRB.GetComponent<Rigidbody2D>(), you're asking playerRB to check the game object it's attached to for a Rigidbody2D component.

but playerRB is null

so it throws an error

GetComponent<Rigidbody2D>() is equivalent to writing this.GetComponent<Rigidbody2D>()

This makes your component ask its game object if it has a Rigidbody2D on it

[harsh coyote]

yeah no im seeing it now

the playerrb.

[crystal prism]

all of these are equivalent, assuming that the references are non-null

playerRB.GetComponent<Foo>();
gameObject.GetComponent<Foo>();
GetComponent<Foo>();

(assuming that we're writing these lines of code inside of a MonoBehaviour)