Mentor for C self study wanted

[cpghost]

On Tue, 23 Oct 2007 23:24:09 +0200
Harald Schmalzbauer <h.schmalzbauer at omnisec.de> wrote:

> #include <stdio.h>
> 
> void main()
> {
>   short nnote;
> 
>   // Numerischen Notenwert einlesen
>   printf("Bitte numerischen Schulnotenwert eingeben: ");
>   scanf("%d",&nnote);
> 
>   switch (nnote)
>   {
>     case 1: printf("Die Note %d entspricht sehr gut.",nnote);
>     break;
>     case 2: printf("Die Note %d entspricht gut.",nnote);
>     break;
>     case 3: printf("Die Note %d entspricht befriedigend.",nnote);
>     break;
>     case 4: printf("Die Note %d entspricht ausreichend.",nnote);
>     break;
>     case 5: printf("Die Note %d entspricht mangelhaft.",nnote);
>     break;
>     case 6: printf("Die Note %d entspricht ungenügend.",nnote);
>     break;
>     default: printf("%d ist keine zulässige Schulnote!");
                      ^^^^^                             ^^^^^

No matching int for "%d" here. It'll print garbage. Change to:
default: printf("%hd ist keine...!", nnote);
                                   ^^^^^^^^

>   }
>   printf("\n");
> }
> 
> P.S.:
> I found that declaring nnote as int soleves my problem, but I
> couldnÄt understand why.
> Another one was the result of default: nnote was -1077942208 instead
> of 9 for example.

The reason for this is that the number of arguments after printf's
format string MUST match the number of %-place holders (unless
you're using exotic stuff like %n, of course). If printf misses
some arguments, it will fetch them from a place that is
implementation dependant (and that almost always means:
you'll get garbage).

Sorry for overlooking your second question... ;)

-cpghost.

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