指针数组功能测试

来源：互联网发布：中国钓鱼运动协会数据编辑：程序博客网时间：2024/05/22 10:38

从字面上理解：指针数组是一个数组，只是数组中存的元素都是指针类型的。

代码测试：

int main()
{
char *n[3]={"gain","strong","much"};
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gain";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

int main()
{
char *n[3]={"gain","strong","much"};
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gai";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

n[0] = 0x8048595
n[1] = 0x8048565
n[2] = 0x804856c

int main()
{
char *n[3]={"gain","strong","much"};
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gaii";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

n[0] = 0x8048595
n[1] = 0x8048565
n[2] = 0x804856c

int main()
{
char *n[3]={"gain","strong","much"};
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gain123";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

n[0] = 0x8048595
n[1] = 0x8048565
n[2] = 0x804856c

int main()
{
char *n[3]={"gain","strong","much"};
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gain123";
n[1] = "test";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0x8048560
n[1] = 0x8048565
n[2] = 0x804856c

n[0] = 0x8048595
n[1] = 0x804859d
n[2] = 0x804856c

int main()
{
char *n[3];
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);

return 0;
}

运行结果：
n[0] = 0xb77b1000
n[1] = 0x804847b
n[2] = 0xb7775000

char *n[3];
int main()
{

printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
n[0] = "gain123";
printf("n[0] = %p\r\n",n[0]);
printf("n[1] = %p\r\n",n[1]);
printf("n[2] = %p\r\n",n[2]);
return 0;
}

运行结果：
n[0] = (nil)
n[1] = (nil)
n[2] = (nil)

n[0] = 0x8048574
n[1] = (nil)
n[2] = (nil)

从上述结果可以看出：
1、指针数组如果进行了初始化，则每个元素的地址是连续的
2、如果对这个元素进行重新赋值，并且内容和原本的不等，则这个地址就会发生改变，
但是这并不会影响那些未被修改的元素的地址，
3、如果指针数组没有初始化，则每个元素的值一开始就是随机的。

4、如果指针数组没有初始化，并且为全局变量，则每个值都为nil。

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