Operator Overloading in C++ programs

Operator overloading is one of the most exciting feature of object-oriented programming. Operator overloading provides normal C++ operators, such as +, -, * etc additional meanings when they are applied to user defined data types. Normally we know that operators like + works only with basic types like int, float etc. Using overloading we can apply these operators on objects also.

Here is one of the C++ programs to demonstrate operator overloading.

#include< iostream.h>

#include< conio.h>

class Count

{

private:

int count;

public:

Count ()

{

count=0;

}

int getCount ()

{

return count;

}

void operator ++ ()

{

count++;

}

};

void main ()

{

clrscr ();

Count c1, c2;

cout<< "\nc1="<< c1.getCount ();

cout<< "\nc2="<< c2.getCount ();

++c1;

++c2;

cout<< "\nc1="<< c1.getCount ();

cout<< "\nc2="<< c2.getCount ();

getch ();

}

The unary operator ++ acts on objects c1 and c2 because the keyword operator is used   and which is a must to overload the ++ operator in the function operator ++ ().  This syntax tells the compiler to call the member function whenever the operator ++ is encountered, provided the operand is of type Count, the class here. If the operator ++ is used on variables of predefined type like int or float then the compiler will use its built-in routine to increment the value of the variable of int or float type.