Question

In C programming I must find a way to error check the inputs given to me by a user. For example, I am asking the user to input either a 1 or a 0 (yes or no responses) to questions. I have had no problem with that part of the code with error checking if the user inputs a different number. My issue however is when the user inputs an alphabetic or special character, my code goes bad really quick, printing the question an infinite amount of times. So I need a code that can quickly check to see if a user entered either 1 or 0 and not a different number, or some alphabetic or special character.

Answer 1

#include<stdio.h>

int main()
{
   char ch;
   printf("Enter input character: ");
   scanf("%c",&ch);
   
   if(ch=='1'){
      printf("It is 1\n");
   }
   else if(ch=='0'){
      printf("It is 0\n");
   }
   else if(ch>='2' && ch<='9'){
      printf("It is a digit\n");
   }
   else if((ch>='a' && ch<='z') || (ch>='A' && ch<='Z')){
      printf("It is an alphabet\n");
   }
   else{
      printf("It is a special character\n");
   }
   return 0;
}