C语言，数组，数组名，数组地址

编写test.c

#include <stdio.h>
#include <stdlib.h>

typedef struct STUDENT_S
{
    char name[12];
    int grade;
    int score;
} __attribute__ ((__packed__))STUDENT_T;

int main()
{
    STUDENT_T *p;
    STUDENT_T a[] ={{"jacky",3,88},{"tom",3,90}};
    p = a;

    printf("sizeof a is %u\n", sizeof(a));
    printf("sizeof a[0] is %u\n", sizeof(a[0]));
    printf("items of a is %u\n", sizeof(a)/sizeof(a[0]));
    printf("addr of a is %p\n", a);
    printf("addr of &a is %p\n", &a);                        // a的值与&a的值，应该相等
    printf("addr of a+1 is %p\n", a+1);                     // a+1的值，应该比a大20
    printf("addr of &a+1 is %p\n", &a+1);                // &a+1的值，应该比我大40
    printf("addr of ++p is %p\n", ++p);
}

gcc -o test test.c

执行test，结果如下：

sizeof a is 40
sizeof a[0] is 20
items of a is 2
addr of a is 0x7fffdf189f80
addr of &a is 0x7fffdf189f80
addr of a+1 is 0x7fffdf189f94
addr of &a+1 is 0x7fffdf189fa8
addr of ++p is 0x7fffdf189f94