Help: Do while not a character

[MC++]

Hello everyone. I am very new to programming and I have just signed up in hopes that I'll be able to learn better and have access to better resources.

I have one question in particular, for now:

Is there a way to make 'while' carry out an argument if the input is a character string instead of a number? For example, I wanted to create a while statement which will output an error message if the user enters a character (i.e. a-z) instead of a numerical value.

I tried while (x != %c) but obviously it doesn't work.

Thanks in advance for any help!

[Adak]

Hello everyone. I am very new to programming and I have just signed up in hopes that I'll be able to learn better and have access to better resources.

I have one question in particular, for now:

Is there a way to make 'while' carry out an argument if the input is a character string instead of a number? For example, I wanted to create a while statement which will output an error message if the user enters a character (i.e. a-z) instead of a numerical value.

I tried while (x != %c) but obviously it doesn't work.

Thanks in advance for any help!

Welcome to the madhouse -- er, *forum*!

In programming, you can OWN the computer, if you just know how! So yes.

   int number;

   while((scanf("%d", &number)) < 1) {
      getchar();
      printf("Enter a NUMBER, please\n");
      
   } 
   
   printf("\nYou entered %d\n",number);

[MC++]

Awesome, thanks a lot!

[MC++]

Okay, so now I've got another issue which I need help with!

So thanks to my friend up there I have sort of resolved the above issue, but there is one problem;

while ((*rooms < 1) || (*rooms > 26)){
            getchar();
            printf("###Error! must be positive\n\n>>> How many rooms are there?: ");
            scanf(" %d", rooms);
            }

What this code block does is that if it detects a character input (or a value outside the specified range ( 1 - 26)) it outputs the ###Error! message line. The problem I'm having is that if the user enters multiple characters (abc) it will spit out the message 3 times. What can I do to counteract this?

Thanks guys!

[Adak]

Try this:

#include <stdio.h>

int main(void) {
   int i, rooms=0;

   while ((rooms < 1) || (rooms > 26)){
      printf("\nEnter the number of rooms [1-26]? ");
      i=scanf(" %d", &rooms);
      if(!i || rooms < 1 || rooms > 26) {
         printf("###Error! Number of rooms must be positive.\n");
         while((i=getchar()) != '\n');
      }
   }
   
   return 0;
}