public class A
{
int a ;
public static void main(String args[])
{
System.out.println(new A().a);
}
}

When will the newly created instance of the class A be garbage collected ? It has no reference variable attached to it, so is it once the class executes ? And what about the member variable a? When will it be garbage collected ? Will it be GCed after the instance is GCed ?
Any clarifications will be very helpful.
Thanks .

code:

---

public class A
{
int a ;
public static void main(String args[])
{
System.out.println(Runtime.getRuntime().freeMemory());
System.out.println(new A().a);
System.out.println(Runtime.getRuntime().freeMemory());
Runtime.getRuntime().gc();
System.out.println(Runtime.getRuntime().freeMemory());
}
}

---

Rekha,
In your code the object created inside the println(..) statement is eligible for GC as soon as the println is over.(Assuming the println(..) doesn't keep another reference to this object. I will check the source code of println(..) ). The reason I had explained in the above paragraph. Please go through it. The simple reason is there is no more reference to it. The JLS says only this. Whenever a object loses all its reference , it is eligible for GC. That's all. JLS doesn't force the mechanism of the GC . It differs from JVM to JVM. The qstn here is when is an object WILL BE ELIGIBLE for GC if at all GC runs. I did some research using SaiRam's code under JDK 1.2.2 in win98. It turns out that when a object loses all its ref it is eligible for GC. So both the anononymous object and the var inside this object(a) are eligible gor GC.

SaiRam,
I played well with your code. Here is the benchMark of the results.
1. If a object is created inside a method and if it does not have any ref it is eligible for GC. As you did you can suggest the GC to do the clean up by saying Runtime.getRunTime.gc(). IF it honours our request the memory WILL BE released before the method returns.
2. Before a method returns, when you keep the reference to all obects created inside a method (not setting them to null) , and call Runtime.getRuntime.gc(), it doesn't have any effect. The object's memory will not be released.
3. When you increase the no. of objects created, inside the method, more memory will be hogged by the system.
4. GC doesn't resolve the circular refs. (i.e) If a obejct is set to null and if it has another instance var as a reference to another object, the referenced object is eligible for GC in the next RUN of GC.
regds
maha anna