When you create an object in Java, such as in the following code:

 Button b = new Button(); 

Java creates a new Button object in memory and sets the value ofvariable b so that it points to this object on the heap. It also sets areference count to the object. When you are finished with the object setthe reference variable to null. This reduces the reference count and,when the reference count reaches zero, the object’s memory can bereclaimed by Java’s garbage collector.

Remember to set unused object references to null:

 b = null;

to help out the Java garbage collector.