Answer Posted / j mathew

class A{
void hallo(){
System.out.println(" hallo of A");
}
}
class B extends A {
void hallo(){ // method overridden.
System.out.println("hallo of B");
}
}
class C extends B {
void hallo(){ // method overridden
System.out.println("hallo of C");
}
}
class Demo {
public static void main(String[] args) {
A a = new A(); // create object of A
B b = new B(); // create object of B
C c = new C(); // create object of C
A r; // create a reference of super class
r=a; // assign object of A to the reference var. r
r.hallo(); // it calls hallo() of class A
r=b; // super class variable can reference a
sub class object.
r.hallo(); // it calls hallo() of class B
r =c; // super class variable can ref. sub
class object.
r.hallo(); // it calls hallo() of class C
}
}

this is how dynamic dispath method works.
overridden methods are resolved at run time rather than
compile time. At compile time it doesn't know which over-
ridden method will be called.
it comes to know at run time, thats why it is called as run
time polymorphism.

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