why?

Question

class A
{
void display()
{
System.out.print("ghosh");
}
}
class Refer extends A
{
public static void main(String args[])
{
A r=new Refer();
r.show();
}
void show()
{
System.out.print("somnath");
}

}

2.

class A
{
void display()
{
System.out.print("ghosh");
}
}
class Refer extends A
{
public static void main(String args[])
{
A r=new Refer();
r.display();
}
void display()
{
System.out.print("somnath");
}

}

why 1st program is not working , 2nd is working ?

Answer 1

In the 1st one r is an object of type a, so show() cannot be found.
You'd need to write:
((Refer)r).show();

The 2nd one is working since it is 'trying' to call display() in class A but display() in class Refer is Overriding it since r has the value of a Refer object. So display() in class Refer is called. You can use the @Override annotation to make it clearer.