consider the following three classes: public class A { private int number; prote

Question

consider the following three classes:

public class A
{
     private int number;
     protected String name;
     public double price;

     public A()
     {
          System.out.println( "A() called");
     }

     private void foo1()
     {
          System.out.println( "A version of foo1() called");
     }

     protected int foo2()
     {
          System.out.println( "A version of foo2() called");
          return number;
     }

     public String foo3()
     {
          System.out.println( "A version of foo3() called");
          return "Hi";
     }
}

public class B extends A
{
     private char service;

     public B()
     {
          super();
          System.out.println( "B() called" );
     }

     public void foo1()
     {
          System.out.println( "B version of foo1() called");
     }

     protected int foo2()
     {
          int n = super.foo2();
          System.out.println( "B version of foo2() called");
          return ( n + 5 );
     }

     public String foo3()
     {
          String temp = super.foo3();
          System.out.println( "B version of foo3() called");
           return ( temp + " foo3");
     }
}

public class C extends B
{
     public C()
     {
          super();
          System.out.println( "C() called");
     }

     public void foo1()
     {
          System.out.println( "C version of foo1() called");
     }
}

What is the output of the following code sequence:

     B b4 = new B();
     System.out.println( b4.foo3() );

A() called
B() called
A version of foo2() called
Hi
B version of foo2() called

A() called
B() called
A version of foo3() called
B version of foo3() called
Hi foo3

A() called
B() called
A version of foo3() called
B version of foo3() called

A() called
B() called
Hi foo3

A() called
B() called
A version of foo2() called
Hi
B version of foo2() called

A() called
B() called
A version of foo3() called
B version of foo3() called
Hi foo3

A() called
B() called
A version of foo3() called
B version of foo3() called

A() called
B() called
Hi foo3

Explanation / Answer

Given code is:

B b4 = new B();
  System.out.println( b4.foo3() );

OUTPUT:

A() called
B() called
A version of foo3() called
B version of foo3() called
Hi foo3

Hence the correct option is b.

Explanation:

The statement B b4 = new B(); will create an object b4 of class B.

The super class of class B is class A.

So B's constructor invokes the constructor of class A is called. So the statement “A() called” is printed."

Then the statement "B() called” is printed."

The statement System.out.println( b4.foo3() ); will call the method foo3() with object b4.

super.foo3(); will output "A version of foo3() called". The value “Hi” is returned.

Then the statement System.out.println( "B version of foo3() called"); will output “ B version of foo3() called".

Then the statement return ( temp + " foo3"); will return “Hi foo3”

Then finally Hi foo3 is printed.

A() called
B() called
A version of foo3() called
B version of foo3() called
Hi foo3

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