c - while循环导致程序挂起

Question

我正在做一项类作业(不评分)，并且不清楚为什么这段代码会导致我的程序“挂起”而不是循环运行。

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

int main()
{
    int nbStars = 0;        // User defines the number of stars to display
    int nbLines = 0;        // User defines the number of lines on which to print

    // Obtain the number of Stars to display
    printf("Enter the number of Stars to display (1-3): ");
    scanf("%d", &nbStars);
    getchar();

    //   Limit the values entered to between 1 and 3
    do {
        printf("Enter the number of Stars to display (1-3): ");
        scanf("%d", &nbStars);

        if (nbStars < 1 || nbStars > 3) puts("\tENTRY ERROR:  Please limit responses to between 1 and 3.\n");
    } while (nbStars < 1 || nbStars > 3);
}

Answer 1

肯定还有其他问题发生，因为您的代码既可以在带有 GCC 的 Linux 上运行，也可以在带有 GCC 的 Windows 7 cygwin 上运行。您能否提供有关您正在使用的输入和环境的更多详细信息？

尝试此代码，看看是否会得到不同的行为:

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

int main()
{
    int nbStars = 0;        // User defines the number of stars to display
    int nbLines = 0;        // User defines the number of lines on which to print

    // Obtain the number of Stars to display
    do
    {
        printf("Enter the number of Stars to display (1-3): ");
        scanf("%d", &nbStars);

        if (nbStars < 1 || nbStars > 3)
        {
            puts("\tENTRY ERROR:  Please limit responses to between 1 and 3.\n");
        }
    }while (nbStars < 1 || nbStars > 3);

    printf("You entered %d\n", nbStars);
    return( 0 );
}