Thread: Determining next date using structures

Hello all, I am trying to construct a c program that accepts a user entered date and then prints the following day. Eventually I need to get it so it is accurate to the month that it is in, but as a first step I am just trying to get the next day part to work correctly. This is the code that I have currently. I think my problem is with my scanf statements but I'm not sure exactly what the problem is. Help would be greatly appreciated.

Code:

#include <stdio.h>

struct date
{
   int month;
   int day;
   int year;
};


int main()
{
int tomorrow;
struct date tom;
 
puts("Enter date in the format m/d/yy\n");
    scanf("%d",&tom.month);
    scanf("%d",&tom.day);
    scanf("%d",&tom.year);


tomorrow=tom.day+1;


printf("Tomorrow's date is: %d/%d/%d \n",tom.month,tomorrow,tom.year % 100);


system ("PAUSE");
return 0;
}

Can you describe the problem you're having? What are you expecting, and what are you actually seeing? What are you entering?

The character '/' does not make part of an integer.
When you type a date as, for instance, "11/27/2012", the first scanf successfuly parses the 11 leaving "/27/2012" pending.
The second scanf catches the '/' and stops (as does the third scanf).

What you can do is enter the date without 'strange' symbols, just spaces:

Code:

puts("Enter month day and year separated by spaces");
if (scanf("%d", &tom.month) != 1) /* error */;
/* ... */

or ignore the character in the scanf itself

Code:

puts("Enter month day and year separated by spaces");
if (scanf("%d", &tom.month) != 1) /* error */;
if (scanf("/%d", &tom.day) != 1) /* error */; /* parse and ignore a / */
if (scanf("/%d", &tom.year) != 1) /* error */; /* parse and ignore a / */

Note, putting it all together, for the last option, is (I think) more usual

Code:

puts("Enter month day and year separated by spaces");
if (scanf("%d/%d/%d", &tom.month, &tom.day, &tom.year) != 3) /* error */;

Also, like I did above, you should always check the return value of scanf ...

Sorry for the late reply, I made some changes suggested but the program is producing a result like: if the user enters '11 14 83' then the program prints 11/1/32. This is the code I have right now after changes have been made.

Code:

#include <stdio.h>

struct date
{
   int month;
   int day;
   int year;
};


int main()
{
int tomorrow;
struct date tom;
 
puts("Enter month, day, and year separated by spaces (mm dd yy):\n");
if (scanf("%d/%d/%d", &tom.month, &tom.day, &tom.year) != 3);




tomorrow=tom.day+1;


printf("Tomorrow's date is: %d/%d/%d \n",tom.month,tomorrow,tom.year % 100);


system ("PAUSE");
return 0;
}

Change this

Code:

scanf("%d/%d/%d", &tom.month, &tom.day, &tom.year

to this

Code:

scanf("%d %d %d", &tom.month, &tom.day, &tom.year

and let scanf do her job

Thank you all so much, I learned alot about the different options for setting up scanf statements. Thanks all!!