Java Polymorphism 2

/* Polymorphic: The reference-type variable of the parent class refers to the object of the subclass or the reference-type variable of the interface type that points to the object of the interface implementation class. Implementing polymorphism in Relationships: interfaces    variables   = new   interfaces implements the object of the class. The methods of */interface dao{  //interfaces are all non-static methods. So a reference to a parent class is always a static method called with the same name     public void add ();    public  Void delete ();} Interface implementation Class Class userdao implements dao{    public void add () {         SYSTEM.OUT.PRINTLN ("Add Employee success!! ");     }       public void delete () {         system.out.println ("Delete employee success!! ");    }}class demo3 {    public static void  Main (String[] args)      {        // The polymorphic         dao d = new userdao () under the realization relation;  // The reference type variable of the interface points to the object of the interface implementation class.          d.add ();     }} 

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Java Polymorphism 2