Are static variables inherited

Aman picture Aman · May 14, 2016 · Viewed 21.7k times · Source

I have read at 1000's of locations that Static variables are not inherited. But then how this code works fine?

Parent.java

public class Parent {
        static String str = "Parent";
    }

Child.java

public class Child extends Parent {
        public static void main(String [] args)
        {
            System.out.println(Child.str);
        }
    }

This code prints "Parent".

Also read at few locations concept of data hiding.

Parent.java

public class Parent {
    static String str = "Parent";
}

Child.java

public class Child extends Parent {
    static String str = "Child";

    public static void main(String [] args)
    {
        System.out.println(Child.str);
    }
}

Now the output is "Child".

So does this mean that static variables are inherited but they follow the concept of data-hiding?

Answer

Sergey Kalinichenko picture Sergey Kalinichenko · May 14, 2016

"Inherited" is not an ideal description of what is happening; a better way to describe it would be to say that static variables are shared among the subclasses of the base class.

All derived classes obtain access to static variables of their base classes. This includes protected variables, mirroring the situation with variables that are inherited.

The concept of hiding applies as well: when a class-specific variable str appears in the Child class, it hides the str variable of the parent class.

Note that the variable str of the base class does not become inaccessible: Child can still access it by fully qualifying with the name of Parent class.