Is calling static methods via an object “bad form”? Why?

by

In my opinion, the real use case that makes this so unreadable is something like this. What does the code below print?

//in a main method somewhere
Super instance = new Sub();
instance.method();

//...
public class Super {
    public static void method() {
        System.out.println("Super");
    }
}

public class Sub extends Super {
    public static void method() {
        System.out.println("Sub");
    }
}

The answer is that it prints “Super”, because static methods are not virtual. Even though instance is-a Sub, the compiler can only go on the type of the variable which is Super. However, by calling the method via instance rather than Super, you are subtly implying that it will be virtual.

In fact, a developer reading the instance.method() would have to look at the declaration of the method (its signature) to know which method it actually being called. You mention

it seems to me that doing this can actually make my life easier so I don’t have to worry about what’s static or not

But in the case above context is actually very important!

I can fairly confidently say it was a mistake for the language designers to allow this in the first place. Stay away.

More Related Contents:

  1. JAVA- JFrame- non static method cannot be referenced from a static context [duplicate]
  2. Why isn’t calling a static method by way of an instance an error for the Java compiler?
  3. Java synchronized static methods: lock on object or class
  4. Why doesn’t Mockito mock static methods?
  5. Java Static vs Instance
  6. Behaviour of final static method
  7. Should private helper methods be static if they can be static
  8. Why can’t I declare static methods in an interface?
  9. Can non-static methods modify static variables
  10. When to use static variables/methods and when to use instance variables/methods in Java? [closed]
  11. Static method in Java can be accessed using object instance [duplicate]
  12. How do I put a method as a parameter in a method call? [duplicate]
  13. Java while loop query [closed]
  14. Cannot refer to a non-final variable inside an inner class defined in a different method
  15. Mocking static methods with Mockito
  16. Are static methods inherited in Java?
  17. In laymans terms, what does ‘static’ mean in Java? [duplicate]
  18. What is the exact meaning of static fields in Java?
  19. How come invoking a (static) method on a null reference doesn’t throw NullPointerException?
  20. Static nested class in Java, why?
  21. Static versus non-static lock object in synchronized block
  22. List of useful environment settings in Java
  23. Does Java support inner / local / sub methods?
  24. In Java, what is the difference between this.method() and method()?
  25. Can I invoke a java method other than main(String[]) from the command line?
  26. Are non-synchronised static methods thread safe if they don’t modify static class variables?
  27. how to call a java method using a variable name?
  28. How do Java programs run without defining the main method?
  29. Difference between Dynamic and Static type assignments in Java
  30. How to automatically log the entry/exit of methods in Java?

Leave a Comment