Can overloading and overriding in java be static polymorphism as well as dynamic polymorphism?

Question

Well this type of questions have been answered already but this confused me. I have spent lot of time going through lots of answer so please go through my question before making it duplicate.

case 1 -

static polymorphism - function overloading dynamic polymorphism - function overriding

links - https://stackoverflow.com/a/12894211/3181738 https://stackoverflow.com/a/20783390/3181738 and many others.

My confusion is that in all the examples dynamic polymorphism is shown using upcasting. What if I don't upcast.

class A{
   public void show(){
       System.out.print("A");
   }
}

class B extends A{
   public void show(){
        System.out.print("B");
   }

   public static void main(String[] s){
      A a = new B();
      a.show(); // upcasting. It is dynamic polymorphism.
      B b = new B();
      b.show(); // Now java compiler can decide so is it still dynamic polymorphism?
   }
}

case 2 -

static polymorphism is achieved via overloading if method is private , static or final.

So what about overloading of public and default methods?

The static members aren't involved in runtime polymorphism. You can't override the static members in a derived class, but you can redefine them — OPK
but you can overload static method and yes I am saying that overloading of static methods is example of static polymorphism. My question is what about public and default — Ishan

ControlAltDel ControlAltDel · Accepted Answer · 2015-08-06T18:27:02

Q1 upcasting: Upcasting and treating a subclass object as if it were a parent class object is the essence of polymorphism. So your question, "What if I don't upcast?" Then you are not using polymorphism

Q2 static polymorphism - method overridding: This is what it's saying:

static: static methods are overwritable, since they are associated with the class, not the object. So for instance, if you have a class with a main method, and then you subclass that, and add a main method to the subclass, when you execute the main method in the subclass, it is statically overridden
- private: private methods are not inherited and cannot be called in the subclass, unless that are statically overridden
- final: final methods are not overriddable. Therefore, redefining them in a subclass creates a statically overridden method

Can overloading and overriding in java be static polymorphism as well as dynamic polymorphism?

3 Answers