相关疑难解决方法(0)

根据此,获取无效指针的值是C++中实现定义的行为.现在考虑以下C程序:

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
    int* p=(int*)malloc(sizeof(int));
    *p=3;
    printf("%d\n",*p);
    printf("%p\n",(void*)p);
    free(p);
    printf("%p\n",(void*)p); // Is this undefined or implementation defined in behaviour C? 
}

但是C中的行为也一样吗？上述C程序的行为是否未定义或实现定义？C99/C11标准对此有何看法？请告诉我C99和C11的行为是否不同.

在这个示例代码中,while循环后指针真的可以无效,并且在编写代码时是否应该考虑到这一点？或者C标准是否被误解和/或有缺陷？

#include <stdio.h>

int main(int argc, char **argv) {
    (void)argc;
    (void)argv;

    int *pointer;
    int object[1];

    pointer = object;
    printf("pointer -before: %p\n", (void*)pointer);

    do {
        int other_object[1];

        printf("a pointer \"just past\" other_object can look like: %p\n", (void*)(&other_object+1));
        printf("address of other_object: %p\n", (void*)&other_object);
    } while (0);
    puts("the lifetime of other_object has ended");
    printf("pointer -after: %p\n", (void*)pointer);
}

可能的输出(在我的机器上运行):

pointer -before: 0x7fff5f744ae4
a pointer "just past" other_object can look like: 0x7fff5f744ae4
address of other_object: 0x7fff5f744ae0
the lifetime of other_object has ended
pointer -after: …