Thread: what is my mistake

Code:

#include <cs50.h>
#include <stdio.h>

int
main(void)
{
    int days = 0;
    do {
        // user is promted to enter number of days in his month
        printf("Enter number of days in the month: ");
        days = GetInt();
        // program shows number of days entered
        printf("You entered %d days.\n" , days);
        // repeat if input is not 28, 29, 30 or 31
    ) while (31 < days < 28);
}

compiler is gcc on fedora and I get this error when compiling

make: warning: Clock skew detected. Your build may be incomplete.

I've had this warning before, and AFAIK, it makes no difference in the final program.

Also, your program is incorrect:
- main should return a number (usually 0) at the end
- you're using ")" instead of "}" on line 15

Your system clock might be skewed. I always recommend installing the ntp package to keep your system clock synchronized to time servers.

Also the test in the while loop doesn't do what you expect.

Code:

while(31 < days < 28);

Shouldn't this be

Code:

while(31 < days && days < 28);

Originally Posted by Click_here

Shouldn't this be

Code:

while(31 < days && days < 28);

So, execute the loop forever?

I kid, I kid. OP needs to change the comparison operators around.

Nope. That will never be true. Actually, it should be:...

OP has wrong logic in there and written incorrectly. Your way is right.

31 < days < 28 would make more sense being
NOT(31 >= days >= 28) -> "Loop when it is not in this domain"

= !((31>=days) && (days >= 28))
= ! (31>=days) || !(days >= 28)

= (31<days) || (days < 28)