What the Concept behind this

Question

hello friends plz check this code
class a
class b extends a
class c extends b
class test
     public void print(a first)
          System.out.println("Here in A");
          System.out.println(first);
     public void print(b first)
          System.out.println("Here in B");
          System.out.println(first);
public class kr
     public static void main(String arg[])
          test t=new test();
          b obj =new c();
          System.out.println(obj);
          t.print(obj) ;
this will print Here in B
if change b obj = new c to a obj = new c
this will print Here in A
what's the concepts behind this
help me thanks
Vivek Nidhi

Answer 1

I saw this a while back:public class A {
public void show(A a) {
System.out.print("A.show(A);\t");
public class B extends A{
public void show(A a) {
System.out.print("B.show(A);\t");
public void show(B a) {
System.out.print("B.show(B);\t");
public class ABTest {
public static void main(String[] args) {
A a = new A();
B b = new B();
A bAsA = new B();
a.show(a);    a.show(b);    a.show(bAsA);
bAsA); System.out.println();
b.show(a);    b.show(b);    b.show(bAsA);
bAsA); System.out.println();
bAsA.show(a); bAsA.show(b); bAsA.show(bAsA);
A); System.out.println();
}You had to guess what the output was.
Almost everybody saidA.show(A);   A.show(A);   A.show(A);  
B.show(A);   B.show(B);   B.show(B);  
B.show(A);   B.show(B);   B.show(B);   when in fact, the correct answer isA.show(A);   A.show(A);   A.show(A);  
B.show(A);   B.show(B);   B.show(A);  
B.show(A);   B.show(A);   B.show(A);   the reason is that although B overrides A.show(A)
which is taken account for at runtime - giving the B.
on the last row - the decision of whether to call
show(A) or show(B) is made at compile time, so
the last column says show(A) - the parameter is of
compiletime type A even if it's runtime type is B -
and the last row is show(A) for similar reasons.
I hope this helps (and makes sense)
Well it makes sense to me but what is really surprising is the result of
bAsA.show(b);
which comes out to be
B.show(A);
while parameter being passed in the method is b which is of type B. Could anybody explain that?