Sams Teach Yourself C in 21 Days

The functionality of these routines should be obvious. The add_hour()function simply

adds to the hours value in the structure, the add_minute()adds to the minutes data mem-

ber, and the add_second()adds to the seconds data member. Listing B3.2 illustrates the

use of these three simple functions with the startandendtime structures.

LISTINGB3.2 time2.cpp. Using the add...functions with the time structure

1: // Program using a time structure with additional functions

2: // for adding time.

3: //

4: #include <iostream.h>

5:

6: struct time {

7: int hours;

8: int minutes;

9: int seconds;

10: };

11:

12: void print_time(struct time tm);

13: void add_hour(struct time *tm);

14: void add_minute(struct time *tm);

15: void add_second(struct time *tm);

16:

17: int main(int argc, char* argv[])

18: {

19: struct time start_time = {7, 15, 20};

20: struct time end_time = {10, 20, 30};

21:

22: // Print initial times

23: cout << “\nStart time: “;

24: print_time(start_time);

25: cout << “\nEnd time: “;

26: print_time(end_time);

27:

28: // Add 1 hour, 1 minute, and 1 second to end time

29: add_hour(&end_time);

30: add_minute(&end_time);

31: add_second(&end_time);

32:

33: // Print final times

34: cout << “\n\nStart time: “;

35: print_time(start_time);

36: cout << “\nNew end time: “;

37: print_time(end_time);

38:

39: return 0;

40: }

41:

42: // Print a time structure in h:m:s format

668 Bonus Day 3

38 448201x-Bonus3 8/13/02 11:19 AM Page 668