Difference between Hidden and overriden methods.

[Somesh Rathi]

Static methods cant be overriden. However they can be hidden.
Whats is meant by Hidden methods ?

[Ganesha Kumar]

Suppose there is a static method in the class A. Another class B extends class A. Here, the static method in A is not inherited by the class B. So, you cannot override it. However you can have a static method which has the same signature as the one in the parent class. This is called as hiding.

[Somesh Rathi]

I have written the following code:

class Parent
{
 static void print()
 {
 System.out.println("In parent");
 }
 }
 class child extends Parent
 {
 }
 public class demo
 {
 public static void main(String args[])
 {
 child c1 = new child();
 c1.print();
 }
 }

Output is : "In Parent"
How is it ? Please clarify ,I'm confused.

[Girish Nagaraj]

1)Suppose there is a static method in the class A. Another class B extends class A. Here, the static method in A is not inherited by the class B. So, you cannot override it. However you can have a static method which has the same signature as the one in the parent class. This is called as hiding.

a)the static method in A is not inherited by the class B-->WRONG.
b)the static method in A is not inherited by the class B ONLY if their is similer static method in class B which has same method prototype as that of static method in the superclass(In which case static method in superclass is hidden).

Hi somesh

I have written a Article on this let me know ur mail id so that it will be usefull to you.

[Filippo Vitale]

As far as I understand means that if:

_ B extends A
_ A has a method like : public static String hello(String name) { return "A: Hello " + name; }
_ B has a method like : public static String hello(String name) { return "B: Hello " + name; }

The "hello" method in B doesn't override the one in A but just it hides it. Examples:

A aa = new A();
aa.hello("Somesh"); // A: Hello Somesh
A ab = new B();
ab.hello("Somesh"); // A: Hello Somesh
B bb = new B();
bb.hello("Somesh"); // B: Hello Somesh
A anull = null;
anull.hello("Somesh"); // A: Hello Somesh
B bnull = null;
bnull.hello("Somesh"); // B: Hello Somesh

BUT if the hello methods are NOT static

A aa = new A();
aa.hello("Somesh"); // A: Hello Somesh
A ab = new B();
ab.hello("Somesh"); // B: Hello Somesh ***
B bb = new B();
bb.hello("Somesh"); // B: Hello Somesh

Filippo

[Filippo Vitale]

Full working code:

class A {
public static String hello1(String name) { return "A: Hello " + name; }
public String hello2(String name) { return "A: Hello " + name; }
}
 
class B extends A {
public static String hello1(String name) { return "B: Hello " + name; }
public String hello2(String name) { return "B: Hello " + name; }
}
 
public class C {
 
public static void main(String[] args) {
A aa1 = new A();
System.out.println(aa1.hello1("Somesh")); // A: Hello Somesh
A ab1 = new B();
System.out.println(ab1.hello1("Somesh")); // A: Hello Somesh
B bb1 = new B();
System.out.println(bb1.hello1("Somesh")); // B: Hello Somesh
A anull = null;
System.out.println(anull.hello1("Somesh")); // A: Hello Somesh
B bnull = null;
System.out.println(bnull.hello1("Somesh")); // B: Hello Somesh
 
A aa2 = new A();
System.out.println(aa2.hello2("Somesh")); // A: Hello Somesh
A ab2 = new B();
System.out.println(ab2.hello2("Somesh")); // B: Hello Somesh ***
B bb2 = new B();
System.out.println(bb2.hello2("Somesh")); // B: Hello Somesh
 
}
}

[Girish Nagaraj]

class Parent
{
static void print()
{
System.out.println("In parent");
}
}
class child extends Parent
{
}
public class demo
{
public static void main(String args[])
{
child c1 = new child();
c1.print();
}
}

As I said before static method in Parent class in inheritted in to Child class-->so you are able to access it as if it is defined in Child class.

[Ganesha Kumar]

Originally posted by Girish Nagaraj:
[QB]1)Suppose there is a static method in the class A. Another class B extends class A. Here, the static method in A is not inherited by the class B. So, you cannot override it. However you can have a static method which has the same signature as the one in the parent class. This is called as hiding.

a)the static method in A is not inherited by the class B-->WRONG.
b)the static method in A is not inherited by the class B ONLY if their is similer static method in class B which has same method prototype as that of static method in the superclass(In which case static method in superclass is hidden).

Can you please tell me why static methods cannot be overridden

[Girish Nagaraj]

1)Hint 1:static methods(also called class methods) belongs to class and not to any particular instance.

2)Hint 2 eclared type of reference cannot be changed where as reference can be made to point to its subclasses.

The Rest is for You to THink!

[Girish Nagaraj]

1)Hint 1:static methods(also called class methods) belongs to class as a whole and not to any particular instance.

2)Hint 2 eclared type of reference cannot be changed where as reference can be made to point to its subclasses(instance it points to can be changed).

The Rest is for You to THink!

[Ganesha Kumar]

Originally posted by Girish Nagaraj:
1)Hint 1:static methods(also called class methods) belongs to class and not to any particular instance.

If static methods belog to the class, then why are they inherited.

[faisal usmani]

Originally posted by Ganesha Kumar:

If static methods belog to the class, then why are they inherited.

No static methods are not inherited, it is a class property and not an object's property, that is why we can also call a static method without creating an instance of the class

[Ganesha Kumar]

Originally posted by faisal usmani:


No static methods are not inherited, it is a class property and not an object's property, that is why we can also call a static method without creating an instance of the class

But the output of the following program is "In parent". That means that the
class child inherits the static method print() in the class Parent

class Parent
{
static void print()
{
System.out.println("In parent");
}
}
class child extends Parent
{
}
public class demo
{
public static void main(String args[])
{
child c1 = new child();
c1.print();
}
}

[Girish Nagaraj]

1)static methods are inherited by the subclass.
2)Here inherited static method becomes property of the subclass.
3)Where as when you inherit instance method it will become property of each instance of the subclass not to subclass as a whole.

Now do you still think static method should not be inherited.

[Somesh Rathi]

Hi Girish,
I'm little confused. It would be great favour if you mail me that article at [e-mail].
Thank you all for your response.
With Best Regards,
Somesh

[sri latha]

Hi Giresh, can u please send your notes to my mailid too. [e-mail]
Thanks in advance

[Harsh Pathak]

ganesh, please email ur notes to me too

i am taking the scjp exam on may 27.

[wise owen]

8.4.8 Inheritance, Overriding, and Hiding