Question

我正在编写以下C程序。在此阶段，程序应从用户那里获取输入并将其存储到变量days中：

#include <stdio.h>
#define SIZE 10

int main(){
    int days = 0;
    int high_temp[SIZE] = {0};
    int low_temp[SIZE] = {0};

    printf("---=== IPC Temperature Calculator V2.0 ===---\n");

    if ((days < 3) || (days > 10)) {

        printf("Please enter the number of days, between 3 and 10, inclusive: %d");
        scanf("%d", &days);

        while ((days < 3) || (days > 10)) {
            printf("\nInvalid entry, please enter a number between 3 and 10, inclusive: ");
            scanf("%d", &days);
            printf("\n");
        }
    }

    for(int i = 1; i < days; i++){
        printf("\nDay %d - High: ", i);
        scanf("%d", &high_temp);

        printf("\nDay %d - High: ", i);
        scanf("%d", &low_temp);
    }

}

但是，在执行期间，问题为days分配了一个荒谬的值：

---=== IPC Temperature Calculator V2.0 ===---
Please enter the number of days, between 3 and 10, inclusive: 87585440

请注意，days初始化为0，并且该值应该在if语句中更改。

Answer 1

此声明

printf("Please enter the number of days, between 3 and 10, inclusive: %d");

具有未定义的行为。从输出的字符串中删除%d。

只要写

printf("Please enter the number of days, between 3 and 10, inclusive: ");

如果您想使用说明符作为提示，请输入

printf("Please enter the number of days, between 3 and 10, inclusive: %%d");

使用%%d的

。

Answer 2

您的printf()调用包含%d的格式说明符，但是您没有在格式后面传递整数。这是未定义的行为，正在从内存中提取一些未知值。

如果要打印days的值，则需要在函数调用中传递它。如果不是，则删除%d说明符。

printf("Please enter the number of days, between 3 and 10, inclusive: %d", days);

Answer 3

走了，希望对您有帮助

#include <stdio.h>
#define SIZE 10
int main(){
int days = 0;
int high_temp[SIZE] = {0};
int low_temp[SIZE] = {0};

printf("---=== IPC Temperature Calculator V2.0 ===---\n");

if ((days < 3) || (days > 10)) {

    printf("Please enter the number of days, between 3 and 10, inclusive: ");
    scanf("%d", &days);

    while ((days < 3) || (days > 10)) {
        printf("\nInvalid entry, please enter a number between 3 and 10, inclusive: ");
        scanf("%d", &days);
        printf("\n");
    }
}

for(int i = 0; i < days; i++){
    printf("\nDay %d - High: ", (i+1));
    scanf("%d", &high_temp[i]);

    printf("\nDay %d - Low: ", (i+1));
    scanf("%d", &low_temp[i]);
}

for (int i = 0; i < days; i++){

   printf("\n Day # %d", (i + 1));
   printf("\n\t High: %d", high_temp[i]);
   printf("\n\t Low: %d", low_temp[i]); 
}

}

程序在执行期间更改变量值

3 个答案: