Thread: Case and switch

Ok, I was trying out the switch and case thing and I have come close to it I think, my program works(in a way)but all I want it to do is take the user input and compare it to the values of the variables and print out the corresponding line, maybe the code will help out a bit:

Code:

#include <stdio.h>

int a=1;
int b=2;
int c=3;
int d;


int main(void)
{
printf("Please enter either numbers 1,2 or 3 to see your selection: ");
scanf("d");

{
	switch(d)
	{
	case 'a':
		printf("This is line 'a'");

	case 'b':
		printf("This is line 'b'");

	case 'c':
		printf("This is line 'c'");
	}

return 0;
}
}

I am not sure if that is even correct as far as the whole switch thing goes but I could use help on the use input thing if you don't mind.

You're trying to take in an integer and check it in the "switch" against an ascii character. You should have been able to find this
problem with a debug session.

Try the following:

Code:

#include <stdio.h>
#include <stdlib.h>

int d;
char input[BUFSIZ];

int main(void)
{
 printf("Please enter either numbers 1,2 or 3 to see your selection: ");

 // take in a character the safe way
 if(fgets(input,BUFSIZ,stdin)!=NULL)
 {
  // convert it to an integer
  sscanf(input, "%d", &d);
 }

 switch(d)
 {
  case 1: printf("This is line 'a'"); break;

  case 2:   printf("This is line 'b'"); break;
 
  case 3:  printf("This is line 'c'"); break;

  default :
   puts(" You didn't enter a 1 or 2 or 3"); break;
 } // end switch(d)

 return (0);
} // end int main(void)

> scanf("d");

Not to mention that nice piece of code...

Quzah.

Ok thats cool and I am going to try it but here is a question about the case thing itself. In my version I was trying to compare the value of 'd' to the cases, how does yours work? I can't see how or what you are checking...I am kinda confused about that if you don't mind explaining it...

Originally posted by CAP
In my version I was trying to compare the value of 'd' to the cases, how does yours work? I can't see how or what you are checking...

Well, in CAP's code this happened

Code:

scanf("d");  /* Wrong, as previously highlighted */

switch(d)
{
case 'a':
	printf("This is line 'a'");

case 'b':
	printf("This is line 'b'");

case 'c':
	printf("This is line 'c'");
}

And in jerryvtts's code, this happened:

Code:

if (fgets(input, BUFSIZ, stdin) != NULL)
{
    sscanf(input, "%d", &d);
}
switch (d)
{
	case 1: printf("This is line 'a'"); break;
	
	case 2: printf("This is line 'b'"); break;
	
	case 3: printf("This is line 'c'"); break;
	
	default: puts(" You didn't enter a 1 or 2 or 3"); break;
}

The structure is basically the same, it just that jerry's will actually compile and run
Also, note that jerry's case statements are checking against numbers, whereas CAP's are checking against character constants.

CAP, quick question, why ask the user to enter 1, 2 or 3, then check their input again a, b and c? Sounds a bit fishy to me

jerry, please can you use code tags for the code (see my sig for an example). It helps make the code readable by keeping the layout as it is in your editor. Thanks.

Like I said I was just trying out the case and switch thing, I wasn't interested in a good copy yet because I would be the only one using it(I am not in any classes or anything). I usually make good copies that make sense to other people later on after things actually work (if only they would though ) Sorry about the not proper syntax and way of handling things but I am trying.