Does variable = null set it for garbage collection

Question

Help me settle a dispute with a coworker: Does setting a variable or collection to null in Java aid in garbage collection and reducing memory usage? If I have a long running

Answer 1

It is useless on local variables, but it can be useful/needed to clear up instance variables that are not required anymore (e.g. post-initialization).

(Yeah yeah, I know how to apply the Builder pattern...)