Java polymorphism invoking overridden method from a subclass.

Case1:--  which method cannot override:-

Q.1  why the final method can not be overridden?

Ø  If we don’t want a method to be overridden we declare it as final.

Q.2  why the static method can not be overridden?

Ø  Method overriding  method hiding

Ø  When you define a static method with the same signature as a static method  in base class it is known as method hiding

Q.3  privet method cannot be overridden?

Ø  Privet method can’t be overridden as they are banded during compile time .there fore we can not event override the privet method in a sub-class.

Example:--

class Test    {

  privet/static/ final  void show   ()   {
System.out.println(“one”)  }

}

class Best extends Test   {

void show()     {

System.out.println(“two”);

}

public static void main(String   args[])   {

Best    b= new Best();

b.show();

}
}

Case  2:-  overriding and synchronize | stritp method

v  The presence of synchronizing/stript modifier with the method has no effect on the rules of overriding.  i.e it's possible that a synchronized /stript method can override a  non-synchronized strictfp one and vice-versa.

Example two in one:

class Test    {

  synchronized /stritfp   void show   ()   {
System.out.println(“one”)  }

}

class Best extends Test   {

void show()     {

System.out.println(“two”);

}

public static void main(String   args[])   {

Best    b= new Best ();

b.show();

Test    b= new Test ();

t.show();

}
}

Method overloading	Method overriding
1.     Same name 2.     Within same class 3.     Different  arguments(no of argument, sequence of argument, and type of arguments are different)	4.     Same name 5.     Different classes. 6.     Same arguments(no of argument, sequence of argument, and type of arguments same) 7.     Inheritance (IS-A) “extends”

 

We can all parent class method in overridden method using  super keyword.

Example:--

class Test    {

void show   ()   {
System.out.println(“one”)  }

}

class Best extends Test   {

void show()     {

super.show ();

System.out.println(“two”);

}

public static void main(String   args[])   {

Best    b= new Best();

b.show();

}
}