C: 当字符数组首指针转化成char *指针，sizeof(*ptr)不为array的size

Posted 2020-11-04 timer_go

#include <stdio.h>
#include <string.h>

int main()
{
    char a[10] = "\0";

    char *pa = (char *)&a;
    char (*paa)[10] = &a;

    printf("-----a[10]----\n");
    printf("a size:%d, pa size;%d, *pa size:%d, *paa size:%d\n", sizeof(a), sizeof(pa), sizeof(*pa), sizeof(*paa));

    return 0;
}

#./aaa
-----a[10]----
a size:10, pa size;8, *pa size:1, *paa size:10

当字符数组的首地址，强制转化成char *指针后： sizeof(*ptr) 不为array的大小；