When do I use super()?

by

Calling exactly super() is always redundant. It’s explicitly doing what would be implicitly done otherwise. That’s because if you omit a call to the super constructor, the no-argument super constructor will be invoked automatically anyway. Not to say that it’s bad style; some people like being explicit.

However, where it becomes useful is when the super constructor takes arguments that you want to pass in from the subclass.

public class Animal {
   private final String noise;
   protected Animal(String noise) {
      this.noise = noise;
   }

   public void makeNoise() {
      System.out.println(noise);
   }
}

public class Pig extends Animal {
    public Pig() {
       super("Oink");
    }
}

More Related Contents:

  1. Java: Calling a super method which calls an overridden method
  2. Difference between Inheritance and Composition
  3. Do subclasses inherit private fields?
  4. Why is there no multiple inheritance in Java, but implementing multiple interfaces is allowed?
  5. How to determine an object’s class?
  6. What is an interface in Java?
  7. Explicitly calling a default method in Java
  8. Why is it not possible to extend annotations in Java?
  9. Bounding generics with ‘super’ keyword
  10. Why to use Interfaces, Multiple Inheritance vs Interfaces, Benefits of Interfaces?
  11. Is there a way to override class variables in Java?
  12. Why do we assign a parent reference to the child object in Java?
  13. Inheritance in Java – creating an object of the subclass invokes also the constructor of the superclass. Why exactly?
  14. Why does the “protected” modifier in Java allow access to other classes in same package?
  15. Is polymorphism possible without inheritance?
  16. Calling super super class method
  17. How do Java method annotations work in conjunction with method overriding?
  18. can’t cast to implemented interface
  19. How can a derived class invoke private method of base class?
  20. Builder Pattern and Inheritance
  21. Are static variables inherited
  22. Why does every object in Java implicitly extend java.lang.Object class?
  23. Java method overriding and variable shadowing
  24. Java generic method inheritance and override rules
  25. When do instance variables get initialized and values assigned?
  26. Does an instance of superclass get created when we instantiate an object?
  27. Force base method call
  28. Is synchronized inherited in Java?
  29. Difference between Dynamic and Static type assignments in Java
  30. Accessing outer class members from within an inner class extending the outer class itself

Leave a Comment