Confused: while loop and characters

This is a discussion on Confused: while loop and characters within the C Programming forums, part of the General Programming Boards category; I'm working on a project for school that prints 4 triangles after taking a size input and character from the ...

  1. #1
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    Feb 2012
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    Confused: while loop and characters

    I'm working on a project for school that prints 4 triangles after taking a size input and character from the user. I want to make a while loop that outputs an error message if the user inputs a value less than 1 or a character when they are asked what size they want the triangles to be. I was able to set up a loop that continues to prompt the user for an integer value if they enter something less than 1(shown here); but, if a character is entered the program goes into an infinite loop. Can anyone point me in the right direction on how to fix my while loop so that it doesn't go into a infinite loop if a character is entered?

    Code:
    #include <stdio.h>
    #include<ctype.h>
    void flush(void)
    {
    while (getchar()!='\n');
    }
    int main(void)
    {
    int size, i, j, valid_input;
    char c, answer;
    do
    {
    Printf(“enter triangle size \n”);
    Scanf(“%i” ,&size);
    while(size <= 0){
        printf("size must be greater than 0 \n");
        printf("\n");
        printf("enter triangle size \n");
        scanf("%i" ,&size);
        }
        flush();
    Thanks in advance and sorry if my question isn't clear...been working on this problem all day and I am feeling a little

  2. #2
    Registered User TheBigH's Avatar
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    How are you getting out of the "do" loop beginning on line 11?
    Code:
    while(!asleep) {
       sheep++;
    }

  3. #3
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    Quote Originally Posted by TheBigH View Post
    How are you getting out of the "do" loop beginning on line 11?
    Sorry, should have mentioned that isn't all the code just the part containing the loop I was having trouble with so that "do" loop is taking care of at the end of the program.

  4. #4
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    I suggest using fgets and sscanf.
    NOTE: C is a case sensitive language; you have multiple mistakes in your code caused by smart quotes I suggest NEVER writing code in MS Word or related software.

    Tim S.
    "Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the universe trying to produce bigger and better idiots. So far, the Universe is winning." Rick Cook

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