指针和数组分析（上）

 1 #include <stdio.h>
 2 int main()
 3 {
 4      int a[5] = { 0 };
 5      int*p = NULL;
 6      printf("a = 0x%X\n",(unsigned int)(a));
 7      printf("a+1 = 0x%X\n", (unsigned int)(a + 1));
 8      printf("p = 0x%X\n", (unsigned int)(p));
 9      printf("p+1 = 0x%X\n", (unsigned int)(p + 1));
10      return 0;
11 }
12 运行结果：
13 a = 0x55FDF8
14 a+1 = 0x55FDFC
15 p = 0x0
16 p+1 = 0x4
17 请按任意键继续. . .

#include <stdio.h>
#define DIM(a) (sizeof(a)/sizeof(*a))
int main()
{
    char s[]={‘h‘,‘e‘,‘l‘,‘l‘,‘o‘};
    char*pbegin = s;
    //如果有一个指针指向了数组最后一个元素的后一个地址，那么这个
    //地址是C语言中的一个擦边球地址
    char*pend   = s+DIM(s);
    char*p = NULL;
    printf("pbegin=%p\n",pbegin);
    printf("pend=%p\n",pend);
    printf("数组元素个数=%ld\n",DIM(s));
    
    for(p=pbegin;p<pend;p++)
    {
        printf("%c",*p);
    }
    printf("\n");
    return 0;
}
运行结果：
book@www.100ask.org:~$ gcc main.c
book@www.100ask.org:~$ ./a.out
pbegin=0x7ffe6de0f620
pend=0x7ffe6de0f625
数组元素个数=5
hello