A tutorial that's a couple of years old uses "var" in func definitions. For example:
func do_something(var player: Node) -> void:
func do_something(player: Node) -> void:
Is there any advantage in doing that?
I think it's the same under the hood, so I do not think it should make a difference either way. I think the version without var is technically the more GDScript way of doing it now, but I think internally the var gets added by the interpreter.