这个c程序怎么了?对其进行调试表明该程序在while(sqroot！= 0)时被击中； [英] What's wrong with this c program? Debugging it suggests that the program is struck at while (sqroot != 0);

问题描述

> 以下是调试过程的屏幕截图
我正在学习用C编程.我正在尝试查找数字是否为镜像，但是该程序编译时没有错误，但没有得到期望的结果.对该程序进行调试表明它在while(sqroot！= 0)时击中了

Here's a screenshot of debugging process
I am learning to program in C. I am trying to find if a number is a mirror image or not, But the program compiles error-free yet didn't give the desired result. Debugging the program shows that it struck at while (sqroot != 0);

    // Mirror number
    #include <stdio.h>
    #include <math.h>
    int main() {
            int num, rev1, rev2, rem1, rem2, sqr, sqroot;
            printf("Enter a number\n");
            scanf("%d", & num);
            sqr = pow(num, 2);
            while (sqr != 0) {
                    rem1 = sqr % 10;
                    rev1 = rev1 * 10 + rem1;
                    sqr = sqr / 10;

            }
            sqroot = sqrt(rev1);

            while (sqroot != 0); {
                    rem2 = sqroot % 10;
                    rev2 = rev2 * 10 + rem2;
                    sqroot = sqroot / 10;
            }

            if (rev2 == num)
                    printf("number is mirror");
            else
                    printf("Not a mirror number");

            return 0;
    }

推荐答案

while (sqroot != 0); { ... }是无限循环.因为;被视为空指令.紧随if (condition)或while (condition)之后的指令(空或非空)被视为if，while，for范围的 only 指令.

while (sqroot != 0); { ... } is an infinite loop. because the ; is considered as an empty instruction. An instruction (empty or not) just after an if (condition) or a while (condition) is considered to be the only instruction of the if, while, for scope.

与写作相同

while (sqroot != 0)
{
    ; /* Do nothing */
}
/* The scope below doesn't belong to the while */
{
    rem2 = sqroot % 10;
    rev2 = rev2 * 10 + rem2;
    sqroot = sqroot / 10;
}

删除;，此问题应得到解决.

Remove the ; and this problem should be solved.

while (sqroot != 0) {
    rem2 = sqroot % 10;
    rev2 = rev2 * 10 + rem2;
    sqroot = sqroot / 10;
}

这篇关于这个c程序怎么了?对其进行调试表明该程序在while(sqroot！= 0)时被击中；的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！