Is there a way to override class variables in Java?

Question

class Dad
{
    protected static String me = \"dad\";

    public void printMe()
    {
        System.out.println(me);
    }
}

class Son extends Dad
{
    protected         


        

Answer 1

No. Class variables(Also applicable to instance variables) don't exhibit overriding feature in Java as class variables are invoked on the basis of the type of calling object. Added one more class(Human) in the hierarchy to make it more clear. So now we have

Son extends Dad extends Human

In the below code, we try to iterate over an array of Human, Dad and Son objects, but it prints Human Class’s values in all cases as the type of calling object was Human.

    class Human
{
    static String me = "human";

    public void printMe()
    {
        System.out.println(me);
    }
}
class Dad extends Human
{
    static String me = "dad";

}

class Son extends Dad
{
    static String me = "son";
}


public class ClassVariables {
    public static void main(String[] abc)   {
        Human[] humans = new Human[3];
        humans[0] = new Human();
        humans[1] = new Dad();
        humans[2] = new Son();
        for(Human human: humans)   {
            System.out.println(human.me);        // prints human for all objects
        }
    }
}

Will print

• human
• human
• human

So no overriding of Class variables.

If we want to access the class variable of actual object from a reference variable of its parent class, we need to explicitly tell this to compiler by casting parent reference (Human object) to its type.

    System.out.println(((Dad)humans[1]).me);        // prints dad

    System.out.println(((Son)humans[2]).me);        // prints son

Will print

• dad
• son

On how part of this question:- As already suggested override the printMe() method in Son class, then on calling

Son().printMe();

Dad's Class variable "me" will be hidden because the nearest declaration(from Son class printme() method) of the "me"(in Son class) will get the precedence.