1. Introduction to Programming
Lecture 32

2. In Last Lecture What is operator overloading ? Overload operators
We also saw the
Binary Operators
Unary Operators
Member and Non-member
operators

3. Example
Complex operator - ( Complex c ) ;

4. Example Complex Complex :: operator - ( Complex c ) { Complex Temp ;
Temp.real = real - c.real ;
Temp.imag = imag - c.imag ;
return Temp ; }

5. void operator -= ( Complex c ) ;
Example
void operator -= ( Complex c ) ;

6. Example void Complex :: operator -= ( Complex c ) { real -= c.real ;
imag -= c.imag ; }

7. Date operator + ( int i ) ;

8. Example Date Date :: operator + ( int days ) { Date Temp ;
int toHold ;
int daysInThisMonth = 0 ;
daysInThisMonth = daysInMonth ( month ) ;
toHold = days ;

9. Example { Temp.month = month + 1 ; if ( Temp.month > 12 )
if ( ( day + days ) >= daysInThisMonth ) {
Temp.month = month + 1 ;
if ( Temp.month > 12 )
Temp.day = 1 ;
Temp.month = 1 ;
Temp.year = year + 1 ; }

10. Example else { toHold = day + days ;
if ( toHold > daysInThisMonth )
Temp.day = toHold - daysInThisMonth ; }
Temp.year = year ;

11. Example { Temp.day = days + day ; Temp.month = month ;
else {
Temp.day = days + day ;
Temp.month = month ;
Temp.year = year ; }
return Temp ;

12. Unary Operator

13. i ++
i --

14. date += 1 ; Same as date ++ ;

15. Date operator++ ( ) ;

16. Unary Member Operator

17. Example void Date :: operator ++ ( ) {
if ( day == daysOfMonth ( day , month , year ) )
if ( month < 12 )
day = 1 ;
month ++ ; }
else
month = 1 ;
year ++ ;
day ++ ;

18. Example } Date Date :: operator + ( int days ) { Date Temp ;
for ( i = 1 ; i < days ; i ++ )
++ Temp ;
return Temp ; }
days = 5

19. Code Reuse

20. < > <= >= ==
Comparison Operator
<
>
<=
>= ==

21. bool

22. bool operator > ( Date d ) ;

23. Example
Date d1 , d2 ;
if ( d1 > d2 )

24. Example
Date date ;
date + 5 ;

25. Example
5 + date ;

26. Interface