循环无限地运行，不管输入的整数是多少

Question

自从我发布这篇文章后，我休息了一段时间，并阅读了我正在学习的 C 编程书籍的一半（哈佛 cs50 书）。我现在应该能够解决这个问题，但我做不到。

无论输入什么整数，程序都在连续循环运行；无限打印 "Good for you..."。

示例代码：

//example 3 version2 from chapter 11, beginner programming in c
#include <cs50.h>
#include <stdio.h>

int main ()
{

        int prefer;

        printf("On a scale from 1 to 10, how happy are you?\n");
        scanf(" %d", &prefer);

        while(prefer >= 1  || prefer <= 10)
                //goal is for program to run while entered int "prefer" is between 1 - 10
                if (prefer > 10)
                {
                        printf("Oh really, now?  Can't follow simple directions, can you?\n");
                        printf("want to try that again?  1 through 10...?\n");
                        scanf(" %d", &prefer);
                }
                else if (prefer >= 8)
                {
                        printf("Good for you!\n");
                }
                else if (prefer <= 5)
                {
                        printf("Cheer up : )\n");
                }
                else if (prefer <= 3)
                {
                        printf("Cheer up, Buttercup!\n");
                }
                else
                {
                        printf("Get in the RIVER with that attitude!\n");
                }
        return 0;
}

Answer 1

运算符 < 和 && 是二元运算符。当我们使用它们时，它会比较左侧和右侧的值。上面的 while 看起来像这样。

while(prefer <= 10 && prefer > 0);

循环无限地运行，不管输入的整数是多少

Loop runs ad infinitum, regardless of int entered

do-while

cs50

cc