Stack n Heap

[usha prithvi]

Hi,

can someone explain difference between stack n heap with examples? and when does stack n heap get used internally?

Thankz

[newgen pras]

Hi ...
Stack is the place where ur primitive local varibles and object references get stored...

Heap is the place where ur object get stored ...

for example
Object ob = new Object();
Object ob1 = ob;

here ob, ob1 will get stored in stack..... the object created by new operator will stay in heap....

Pls correct me if i am wrong any way

[Pramod Chris]

Just to add, object references are stored in the stack if created within a method, else it is stored in the heap. Objects created are stored on the heap. Stack memory is the programs memory and Heap memory is outside the program.

[newgen pras]

I don't think object reference will get stored in Heap... If that is going to be stored in Heap ..how it will get garbage collected ..pls explain me ...

[Steve Morrow]

I don't think object reference will get stored in Heap...

public class Foo {
 
    public static void main(String[] args) throws Exception {
        new Bar();
    }        
} 
 
class Bar {
    Object o = new Object();
}

The Object reference 'o' is stored on the heap, as a member of the Bar instance.

[Maulin Vasavada]

Hi newgen

about your comment - "how it will get garbage collected",
I don't think GC would work that way. In fact it does run on "Heap" by starting from top level objects and then following object graphs to see which objects can be GCed.

Regards
Maulin

[fred rosenberger]

The object REFERENCE is stored on the stack, but the object itself is in the heap ( think).

[Steve Morrow]

The object REFERENCE is stored on the stack, but the object itself is in the heap ( think).

See my previous reply. Local references are stored on the stack. Instance fields (references, primitives, etc.) are on the heap.