what is wrong with this simple program?

This is a discussion on what is wrong with this simple program? within the C Programming forums, part of the General Programming Boards category; This is a simple little menu which doesn't work. After a character is inputted, user input is skipped for the ...

  1. #1
    Registered User Dave Jay's Avatar
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    Mar 2002
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    what is wrong with this simple program?

    This is a simple little menu which doesn't work. After a character is inputted, user input is skipped for the next scanf statement if the loop continues. If response is declared to be int, it works, why doesnt this work for char?


    Code:
    #include <stdio.h>
    
    int main()
    {
    char response;
    
      do {
       printf("\nMENU (4 to quit)\n");
       printf(" :");
       scanf("%c",&response);
       
       switch (response) {
         case '1':  printf("case 1 reached\n");               
                    break;
         case '2':  
                    printf("case 2 reached\n");
                    break;
         case '3':  
                    printf("case 3 reached\n");
                    break; 
       }
      } while(response != '4');
    
      return 0;
    
    }

  2. #2
    Just Lurking Dave_Sinkula's Avatar
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    Quote Originally Posted by Dave Jay
    This is a simple little menu which doesn't work. After a character is inputted, user input is skipped for the next scanf statement if the loop continues. If response is declared to be int, it works, why doesnt this work for char?
    You type "1\n" (the digit one followed by the enter key), right? The '\n' is not equal to '1', '2', '3', or '4'. The input buffer does not need to wait for you to type an answer if there is data ready and waiting.

    http://faq.cprogramming.com/cgi-bin/...&id=1043284392
    7. It is easier to write an incorrect program than understand a correct one.
    40. There are two ways to write error-free programs; only the third one works.*

  3. #3
    Registered User Dave Jay's Avatar
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    Mar 2002
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    yeah but

    why does the input buffer flush when response is declared as int?

  4. #4
    Just Lurking Dave_Sinkula's Avatar
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    Quote Originally Posted by Dave Jay
    why does the input buffer flush when response is declared as int?
    Short answer: it doesn't.
    7. It is easier to write an incorrect program than understand a correct one.
    40. There are two ways to write error-free programs; only the third one works.*

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