Polymorphism

 

  •     A concept that is made by the addition of Overriding, Inheritance, Casting is called Polymorphism.

           Refer to this code sample,


           class A {
           void print (){
           System.out.println ("A");
           } 
           }
           class B extends A{
           void print (){
           System.out.println ("B");
           }
           }
           B b  = new B () ;
           b.print();
           A a = new A () ;
           a.print () ;
           A a1 = new B () ;
           a1.print();

         You will be able to see,
  • Orange colour parts are overriding points.
  • Red colour part  is Inheritance    
  • Pink colour highighted part is Casting (Used technic (Up casting))   
  • Blue colour part is the calling of sub class method.

       In the upcasting object (Highlighted Pink), you can see that,
  •  A -- Super class reference
  • The owner is B because, the object is made by B's reference.


  • Casting a method of a super class in a subclass or after overriding is called polymorphism. (The process of creating a subclass method by using a superclass reference by using inheritance, casting, overriding is called polymorphism.)

 
         Refer to these Java objects,

  1. Animal a1 = new Animal ()
  2. Animal a2 = new Dog ();
  3.  Animal a3 = new BabyDog ();
         
         If you referred to this carefully, you will be able to see that,
  • Red colour words are the super class references 
  • 1st object is a super class object
  • 2nd, 3rd are sub class objects

  • Because of the animal Dog super class, the object can be created by casting even the baby dog suitable place.
-(10th Article)        
                                                                                                    


Thank You!
                                                                                                           


                                                                                                            
                     
                                                                                                       -Article about Java by Hirun Yapa



 

           

           
           

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