Question

 Explain operator overloading with suitable example. Write any two characteristics of operator overloading.

Answer 1

(1) The mechanism of giving some special meaning to an operator is called as operator overloading.
(2) In C++, the user defined data types behave in much the same way as the built-in data types.
(3) For instance, C++ permits to add two varibles of user-defined data types with the same syntax as the basic types. This means that C++ has the ability to provide operators with a special meaning for a data type. This is nothing but operator overloading.
(4) Operator overloading provides a flexible option for the creation of new definitions for most of the C++ operators.
(5) When an operator is overloaded, its original meaning is not lost. For instance, the operator+ has been overloaded to add two vectors, can still be used to add two integers.
(6) To define an additional task to an operator; a special function called ‘operator function’ is used to specify the relation of the operator to the class.
(7) Following program shows overloaded ++ operator
e.g. //increment counter variable with ++ operator
#include <iostream.h>
class counter
{
private:
int count;
public:
counter ( )
{count = 0;}
int get_count ( )
{return count;}
void operator ++ ( )
{count ++;}
void main ( )
{ counter C1, C2;
cout <<“C1 =” <<C1.get_count ( );
cout <<“C2 =” <<C2.get_count ( );
C1++;
C2++;
++C2;
cout <<“C1 =” <<C1.get_count ( );
cout <<“C2 =” <<C2.get_count ( );
} 
In the above program, two objects of class counter : C1 and C2 are created. They are intially 0. Then using overloaded ++ operator, increment C1 once C2 twice and display resulting values.
(8) Characteristics of operator overloading :
(i) Operator overloading concept extends capability of operators to operate on user-defined data.
(ii) It can also be applied to data conversion.
(iii) Using operator overloading technique, user-defined data types behave in much the same way as the  built-in types.