Answer Posted / amr

well Polymorphism means one name implies many forms , which introduces generic programming . Polymorphism happens in the inheritance hierarchy , so that low level abstractions which extend higher level abstraction can override
(re-implementing a method of superclass in a subclass with identical signature) the implementation of the higher level abstraction .

example :

class vehicle {
void accelerate()
}

class car extends vehicle{
void accelerate()
{
S.O.P("um a car");
}
}
class bike extends vehicle{
void accelerate()
{
S.O.P("um a bike");
}
}

now bike and car vehicles .
so we can say

Vehicle[] v = new Vehicle[2];
v[0]= new Car();
v[1]=new Bike();

so here i have array of vehicles
i can do the following (generically )

for (i=0;i<v.length;i++)
v[i].accelerate();
-------
output:
um a car
um a bike

like i say ok guys all of u r vehicles so all of u can accelerate so do it everyone on his own way .

now that was a very polymorphic piece of code
because every time i call the method accelerate on an object the JVM will do Dynamic resolution and invoke the corresponding method of that object .

so not only overriding is polymorphic but we should keep a consistent inheritance hierarchy or abstraction levels .

---

method overloading is another form of polymorphism but its easier to implement because at compilation time all the method calls are resolved .

for ex
-----

class Add {

int add(int a, int b)
{
return a+b;
}
float add(float a,float b)
{
return a+b;
}
}
so be careful with overloading because methods are identified by it signature which is
-return type
-name
-parameters number
-parameters types
-order of parameters

since overloading means the same name then we are left with
-return type
-parameters number
-parameters types
-order of parameters

now lets see this code

Add a = new Add();
int x =a.add( 2 , 3 );
float y = a.add( 2.2, 3.4);
-----------

now i guess this covers the polymorphism types
what do u say

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