Question

If I have a loop and create a new object inside it

for ( int i ; i < 10 ; i++)
{
  MyObject obj = new MuObject();
   obj.use();
}

Do I need to say obj = null, inside the loop at the beginning or end to release memory used by that object , or by using “new” that object will be send to GC ? and can I see this in terms of memory usage ?

update : so in case I have big object and long loop , should I assign the object to null or no ?

Answer 1

Check this: http://javarevisited.blogspot.com/2011/04/garbage-collection-in-java.html

“An Object becomes eligible for Garbage collection or GC if its not reachable from any live threads or any static references”. After the loop ends, the objects that you created inside the loop do not have any external references pointing to them and are eligible for garbage collection.

EDIT:
If you want to see memory usage, you can profile your application using an IDE that has such a feature. For example, NetBeans has a nice interface that shows live memory usage for object allocation.

EDIT 2:
“so in case I have big object and long loop , should I assign the object to null or no ?”
No, you do not need to do this. Once one iteration of the loop is complete, there are no active references to any objects created in that iteration so it does not matter that you have a long or short loop.