Why Does My Java Subclass Print the Parent Class's Static Variable Instead of Its Own?

Overriding Class Variables in Java: A Hidden Mystery

The question arises from an intriguing code snippet that revolves around a class hierarchy, specifically around a parent class named Dad and its child class, Son. Both classes possess a class variable named me, intended to represent their identity. However, the issue arises when the doIt() method, which instantiates a Son object and calls its printMe() method, prints "dad" instead of the expected "son."

Can Class Variables Be Overridden?

To answer this, we delve into the concept of inheritance and overriding in Java. Overriding refers to the ability of a subclass to modify the behavior of a method defined in its superclass. However, this concept does not extend to class variables.

Hiding vs. Overriding

In the case of class variables, what happens is not overriding but rather "hiding." When a subclass declares a class variable with the same name as one in its superclass, it hides the inherited variable rather than replacing it. The hidden variable is effectively masked from view within the subclass.

The Hidden Value

Returning to the example, the declaration of me in Son hides the me variable inherited from Dad. However, the hidden variable in Dad retains its value, "dad," and is the one that is accessed and printed in the printMe() method.

Alternative Solution

To achieve the desired outcome of printing "son," an alternative approach is to utilize instance variables (non-static variables) defined within the constructor of the child class. This method allows the subclass to have its own distinct identity without affecting the class variable of its superclass.

Conclusion

In essence, there is no direct mechanism for overriding class variables in Java. The relationship between a subclass and its superclass involves hiding and inheritance, allowing for the subclass to have its own unique characteristics without modifying the original values of the parent class. In cases where distinct identities are desired, employing instance variables offers a more suitable solution.

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