Does assigning objects to null in Java impact garb

Question

Does assigning an unused object reference to null in Java improve the garbage collection process in any measurable way?

My experience with Java (and C#) has taught me that is often counter intuitive to try and outsmart the virtual machine or JIT compiler, but I've seen co-workers use this method and I am curious if this is a good practice to pick up or one of those voodoo programming superstitions?

Answer 1

It depends.

Generally speaking shorter you keep references to your objects, faster they'll get collected.

If your method takes say 2 seconds to execute and you don't need an object anymore after one second of method execution, it makes sense to clear any references to it. If GC sees that after one second, your object is still referenced, next time it might check it in a minute or so.

Anyway, setting all references to null by default is to me premature optimization and nobody should do it unless in specific rare cases where it measurably decreases memory consuption.