overriding a variable in java

Question

public class Foo {
      public int a = 3;
    public void addFive(){
        a += 5; System.out.print("f ");
    }
}

---

public class Bar extends Foo {
    public int a = 8;
    public void addFive(){ 
        this.a += 5; 
        System.out.print("b " ); 
    }
}

---

public class Test {
    public static void main(String args[]){
        Foo f = new Bar(); 
        f.addFive();
        System.out.println(f.a);
    }
 }

I am getting output b 3 .why it is not giving b13 as output.Can anyone please explain.

Answer 1

Assuming class Foo is declared as below

class Foo 
{

    public int a = 3;

    public void addFive()
    { 
        a += 5; 
        System.out.print("f ");
    }
}

1. Variables have no concept of overriding. They are just masked.
2. It is printing 3 because, when you use a superclass reference to access a variable, it accesses the variable declared in superclass only. Remember that superclass doesn't know anything about subclass.