Polymorphism is the ability of an object or reference to take many different forms at different instances. These are of two types one is the "compile time polymorphism" and other one is the "run-time polymorphism".

In this method object is bound to the function call at the compile time itself.

In this method object is bound to the function call only at the run time.

#include <iostream.h>
class Value 
  {
    protected:
    int val;
    public:
    void set_values (int a)
      { val=a;}
  };
class Cube: public Value 
  {
  public:
  int cube()
    { return (val*val*val); }
  };
int main () {
  Cube cb;
  Value * ptr = &cb;
  ptr->set_values (10);
  cout << "The cube of 10 is::" << cb.cube() << endl;
  return 0;
}

    The cube of 10 is:: 1000

In the above OOPs example "Cube" is a derived class of "Value". To implement polymorphism a pointer "ptr" is used to reference to the members of the class "Cube". This is an example for "Compile time polymorphism."