Limitations of Increment and Decrement Operators

The prefix notation causes a variable to be updated before its value is used in the expression, whereas the postfix notation causes it to be updated after its value is used. However the statements

X1 = A++; and X2 = ++A has exactly the same effect;

When ++ and – operator are overloaded, there is no distinction between the prefix and postfix overloaded operator function.

This problem is avoided in the implementation of C++, which provides addition syntax to express and distinguish between prefix and postfix overloaded operator function. The syntax for overloaded operator function is

Return_type operator++(int)

Sample Program

#include <iostream.h>

class post

{

int val;

public:

post(void)

{

val = 1;

}

int operator++(void)

{

return (++val);

}

int operator++(int)

{

return(val++);

}

};

void main()

{

int x1, x2;

post A;

x1 = A++;

x2 = ++A;

cout<<”x1 is “<<x1<<endl;

cout<<”x2 is “<<x2<<endl;

}