How does inheritance of instance fields work in this particular code?

Question

class A
{
    int a = 2, b = 3;
    public void display()
    {
        int c = a + b;
        System.out.println(c);
    }
}
class B extends A
{
    int a = 5, b =          


        

Answer 1

Why does the output come out as 5,5? And not 5,11?

Whenever we have same instance variables (applicable to class variable as well) in a class hierarchy, the nearest declaration of the variable get the precedence. And in this case, nearest declaration of a and b from display () method is A’s. So class B’s instance variables go hidden. Hence in both cases, 5 gets printed.

How would the y.display() method work?

Another alternative is to have getter in both classes to get value of a and b.

    class A
{
    int a = 2, b = 3;
    public int getA() {
        return a;
    }

    public int getB() {
        return b;
    }
    public void display()
    {
        int c = getA() + getB();
        System.out.println(c);
    }
}
class B extends A
{
    int a = 5, b = 6;
    public int getA() {
        return a;
    }

    public int getB() {
        return b;
    }
}
class Tester
{
    public static void main(String arr[])
    {
        A x = new A();
        B y = new B();
        x.display();
        y.display();
    }
}

Prints

• 5
• 11