Java Covariants

Question

public class CovariantTest {
    public A getObj() {
        return new A();
    }

    public static void main(String[] args) {
        CovariantTest c = new SubCov         


        

Answer 1

package ch2;

class CovariantTest
{
    public A getObj()
    {
        return new A();
    }
}

class SubCovariantTest extends CovariantTest
{
    public B getObj()
    {
        return new B();
    }
}

public class TestPrg
{
    public static void main(String[] args)
    {
        CovariantTest c = new SubCovariantTest();
        System.out.println("c.getObj().x :: "+c.getObj().x);
        System.out.println("c.getObj().getX() :: "+c.getObj().getX());
    }
}

class A
{
    int x = 5;

    int getX()
    {
        return x;
    }
}

class B extends A
{
    int x = 6;

    int getX()
    {
        return x;
    }
}

Simple... Polymorphism is only applicable for functions. Not variables.

Variables will be resolved during compile time.