无法理解静态变量的行为

Question

#include <stdio.h>

main()
{

    int i = 10;
    static int a = i;
    if(a==10)
        printf("yes 1st comparision is equal\n");
    else
        printf("no 1st comparision is not equal\n");
    if(i==10)
        printf("yes 2nd comparision is equal\n");
    else
        printf("no 2nd comparision is not equal\n");

    a=15;
    if(a==i)                                              
        printf("yes 3rd comparision is equal\n");
    else
        printf("no 3rd comparision is not equal\n");

}

为什么a重新初始化为15，输出是no 3rd comparision is not equal而输出应该是 yes 3rd comparision is equal?

Answer 1

您正在比较的是两个单独的值。

从您的问题来看，您似乎期望的是引用(通常使用指针来实现)。

这个例子与静态无关，因为函数main只输入一次。

如果您想要引用，这是一个非常简化的用法:

#include <stdio.h>

int main() {
    int i = 10;
    int* const a = &i;
    if (*a == 10)
        printf("yes 1st comparision is equal\n");
    else
        printf("no 1st comparision is not equal\n");
    if (i == 10)
        printf("yes 2nd comparision is equal\n");
    else
        printf("no 2nd comparision is not equal\n");

    *a = 15;

    if (*a == i)
        printf("yes 3rd comparision is equal\n");
    else
        printf("no 3rd comparision is not equal\n");

    return 0;
}