calling static method without creating any instance

[gaya3]

Hi all,
How does the static method is called without creating any instance for that class?How does this functionality works?Thanks in Advance.

-Thanks & Regards,
Hamsa

[JosAH]

Hi all,
How does the static method is called without creating any instance for that class?How does this functionality works?Thanks in Advance.

-Thanks & Regards,
Hamsa

A method is a message you send to something: a non static method is sent to
an object and a static method is sent to the class itself; like this:

[code=java]
class C {
static void s() { ... } // static method
void d() { ... } // non-static method
}
...

C.s(); // call static method
C c= new C(); // construct object
c.d(); // call dynamic method
c.s(); // silly way to call static methd
[/code]

kind regards,

Jos

[gaya3]

A method is a message you send to something: a non static method is sent to
an object and a static method is sent to the class itself; like this:

[code=java]
class C {
static void s() { ... } // static method
void d() { ... } // non-static method
}
...

C.s(); // call static method
C c= new C(); // construct object
c.d(); // call dynamic method
c.s(); // silly way to call static methd
[/code]

kind regards,

Jos

Thank u Jos...
what you have explanied is rite..
but i like to know...why we doesnot require any object for calling static method..
can u pl elaborate..

-Thanks & Regards,
Hamsa

[JosAH]

Thank u Jos...
what you have explanied is rite..
but i like to know...why we doesnot require any object for calling static method..
can u pl elaborate..

-Thanks & Regards,
Hamsa

Just suppose you'd need an object to call a static method. There would be no
need for the method to be static would it? Consider a class a special kind of
object, something like the mother of all objects (instantiations ) of the class.
Then a static method is just a method that you call given a (special) object.

kind regards,

Jos

[gaya3]

Just suppose you'd need an object to call a static method. There would be no
need for the method to be static would it? Consider a class a special kind of
object, something like the mother of all objects (instantiations ) of the class.
Then a static method is just a method that you call given a (special) object.

kind regards,

Jos

ok..Jos.. I ll put you the question in other way..
what is the difference between calling the static method with its class name
and with objectof that class..
For Example
[code]
public class Static_test
{
public static void sample_method()
{
//code
}
public static void main(String args[])
{
sample_method() --------> works fine
Static_test s1 = new Static_test();
s1.sample_metho d(); --------> works fine

}
}
Difference please..

-Thanks & Regards,
Hamsa

[JosAH]

ok..Jos.. I ll put you the question in other way..
what is the difference between calling the static method with its class name
and with objectof that class..

There is no difference but calling a static method through an object is considered
'bad style'; Eclipse even warns you about it if you do so. Calling a static method
through the class name can be a teensy-weensy bit faster but that's all.

kind regards,

Jos

[gaya3]

There is no difference but calling a static method through an object is considered
'bad style'; Eclipse even warns you about it if you do so. Calling a static method
through the class name can be a teensy-weensy bit faster but that's all.

kind regards,

Jos

ok.. Jos.. when i was surfing through google.. i have got an explanation for that static method invoke as follows.."When we create a class memory will be allocated in Heap. And Stack will keep track of the Starting Address of the Class. If you call any static method. They will be reffered from the Address of the Class. <


A a = null;

In that scenario a object 'a' is created and assigned to the starting the address if we intailze the object another address will be allocated. so a will be reffeered to the 'A'. So you can access the Static Method."

can you please elaborate..what they mean in above statement..plea se help..

-Thanks & Regards,
Hamsa

[JosAH]

ok.. Jos.. when i was surfing through google.. i have got an explanation for that static method invoke as follows.."When we create a class memory will be allocated in Heap. And Stack will keep track of the Starting Address of the Class. If you call any static method. They will be reffered from the Address of the Class. <


A a = null;

In that scenario a object 'a' is created and assigned to the starting the address if we intailze the object another address will be allocated. so a will be reffeered to the 'A'. So you can access the Static Method."

can you please elaborate..what they mean in above statement..plea se help..

-Thanks & Regards,
Hamsa

That is just a filthy little trick. Suppose class A has a static method s(). The
following will work (i.e. not throw a NullPointerExce ption):

[code=java]
A a = null;
a.s();
[/code]

The compiler figures out that it has to call A's static method s() and simply
ignores variable a which is null; it has the class A to find the method s(),
it doesn't need variable a for that at all.

kind regards,

Jos

[gaya3]

That is just a filthy little trick. Suppose class A has a static method s(). The
following will work (i.e. not throw a NullPointerExce ption):

[code=java]
A a = null;
a.s();
[/code]

The compiler figures out that it has to call A's static method s() and simply
ignores variable a which is null; it has the class A to find the method s(),
it doesn't need variable a for that at all.

kind regards,

Jos

Jos please dont mind.. still i'm not satisfy with the solution..
I may be clear if u explain me the following question...
if we declare variable or method as static what actually happens?

-Thanks & Regards,
Hamsa

[JosAH]

Jos please dont mind.. still i'm not satisfy with the solution..
I may be clear if u explain me the following question...
if we declare variable or method as static what actually happens?

-Thanks & Regards,
Hamsa

Nothing much happens actually; the compiler generates a symbolic address for
the static method which gets resolved to a 'real' address when the class is
loaded. If you're curious for the gory details read the JLS.

kind regards,

Jos