Thread: Displaying dates bug

The program is supposed to have the user enter a date in the format of day month year. Example 12 12 2012 then dispaly it as 12th december 2012.
When I run the code it displays 12h december 2012 or 1t december 2012 if the day entered is 1

Code:

/*exercise 3.2 dates*/
#include
<stdio.h>
int
 main(void)
{
    
int monthnumber = 0;
    
int day = 0;
    
int year = 0;
    
char ending = 0;
    printf(
"\nEnter the date as three integer values for the day,the month and the year: \n");
    scanf("%d %d %d", &day, &monthnumber, &year);
    
/*configure ending*/
    
if (day >=4 && day <= 30)
        ending = 'th';
    
elseif (day == 1 || day == 21 || day == 31)
        ending = 'st';
    
else
        ending = 'rd';
    
/*print day*/
    printf("\n%d%c", day, ending);
    
/*Print Month*/
    
switch (monthnumber)
    {
    
case 1:
        printf(" January");
        
break;
    
case 2:
        printf(" February");
        
break;
    
case 3:
        printf(" March");
        
break;
    
case 4:
        printf(" April");
        
break;
    
case 5:
        printf(" May");
        
break;
    
case 6:
        printf(" June");
        
break;
    
case 7:
        printf(" July");
        
break;
    
case 8:
        printf(" August");
        
break;
    
case 9:
        printf(" September");
        
break;
    
case 10:
        printf(" October");
        
break;
    
case 11:
        printf(" November");
        
break;
    
case 12:
        printf(" December");
        
break;
    }
    
/*print year*/
    printf(" %d", year);
}

The most glaring thing about your code is that you completely ignore the "nd" suffix. Also, in this comparison you mean day > 23 not day < 23

Code:

((day > 3 && day < 21) || (day < 23 && day < 31))

Another point, the case statement for the months is overkill. You could do this instead:

Code:

const char *months[] = {"January", "February", "..."};
printf("%s", months[monthnumber]);

This deals only with the char append for the day number.

Replace your logic for this completely.


1) Use int n=day number % 10, to assign the right most digit of the day number, to n.

2) Use a small char arrray like this:

Code:

char append[4][4]={
{"th"},
{"st"},
{"nd"},
{"rd"},
{"th"}
};

Now the logic becomes simple:

Code:

#include <stdio.h>

int main(void) {
   int i,n;
   char append[5][4] = {
      {"th"},
      {"st"},
      {"nd"},
      {"rd"},
      {"th"},
   };
   /* i represents the day number, here */
   for(i=1;i<110;i++) {
      n = i % 10;           //get the value of the dates right most digit, assigned to n
      if(i > 10 && i < 14)
         n=0;
      else if(n>4)
         n=4;
      
      printf("%4d%-3s ",i,append[n]);

   }

   printf("\n\n");
   return 0;
}

Originally Posted by prafiate

I haven't learned arrays yet, so I dont really understand the correction. I also don't quite pick up on the logic with the modulus.

What is "January" then? It's a string, and strings are one or more char's, ending with an end of string char: '\0'.

a char array is simply something that holds char values - of course!

Modulus is just used here to get the right most digit: Say you had 512, and you had code like:

Code:

int n;

n = 512 % 10;

What would n equal? 2 of course. Because we use a base 10 number system. Think about it - divide 512 by 10 and what's left over? 2!

Divide 123 by 10, and what's left over? 3, etc.
So 123 % 10 equals 3.

etc.

It's hard to do much programming involving letters, without using char arrays. Not worth spending a lot of time trying to work with char's, without learning about (and using), char arrays.

You could get by using two separate char's, instead of a string, but why? Move forward, and make that jump - because you won't be using single char's to work with strings in the future, anyway. Nobody does.

Originally Posted by prafiate

Also my book hasn't gotten to character strings yet. So I guess i'll have to find another way to configure the ending for the days

From the comment in your code, it seems these may be practice exercises? if so I'd suggest attempting to solve the problem with the knowledge you've been taught up till now - from the book. The exercises are there to make sure you know what you've covered. Trying to jump ahead and using code you haven't really learned yet could have unexpected and frustrating consequences.

Saying that, one solution to your problem would be to use multiple if and print statements to print out the characters you want.

I'm also interested to know what book you are learning from as this seems to be the second time main() doesn't return an int. You may have to burn it and get a standard compliant

I say scrap all that hard work and just use this...

system("ECHO %DATE%");



This is a simple program...

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
system("ECHO %DATE%");
system("PAUSE");
return 0;
}