C语言 多重指针--整型&字符&字符串 int**pp

Posted 2021-09-07 DQ_CODING

介绍

多重指针:一个指针指向另一个指针
离值越近的指针级别越大:一级

内存布局

代码

图示:

多重指针–整型

#include<stdio.h>
#include<string.h>
//多重指针--整型

//二级指针
void two()
{
	printf("二级指针:\\n");
	int a=896;
	int *p=&a,**pp=&p;
	printf("a=%d self-address=%p\\n",a,&a);
	printf("a=%d address=%p self-address=%p\\n",*p,p,&p);
	printf("a=%d address=%p self-address=%p\\n",**pp,pp,&pp);
}

//三级指针
void three()
{
	printf("三级指针:\\n");
	int a=57877777;
	int *p=&a,**pp=&p,***ppp=&pp;
	printf("a=%d self-address=%p\\n",a,&a);
	printf("a=%d address=%p self-address=%p\\n",*p,p,&p);
	printf("a=%d address=%p self-address=%p\\n",**pp,pp,&pp);
	printf("a=%d address=%p self-address=%p\\n",***ppp,ppp,&ppp);
}

int main()
{
	two();
	three();
	getchar();
	return 0;
}

多重指针–字符

#include<stdio.h>
#include<string.h>
//多重指针--字符

//二级指针
void two()
{
	printf("二级指针:\\n");
	char a='i';
	char *p=&a,**pp=&p;
	printf("a=%c self-address=%p\\n",a,&a);
	printf("a=%c address=%p self-address=%p\\n",*p,p,&p);
	printf("a=%c address=%p self-address=%p\\n",**pp,pp,&pp);
}

//三级指针
void three()
{
	printf("三级指针:\\n");
	char a='y';
	char *p=&a,**pp=&p,***ppp=&pp;
	printf("a=%c self-address=%p\\n",a,&a);
	printf("a=%c address=%p self-address=%p\\n",*p,p,&p);
	printf("a=%c address=%p self-address=%p\\n",**pp,pp,&pp);
	printf("a=%c address=%p self-address=%p\\n",***ppp,ppp,&ppp);
}

int main()
{
	two();
	three();
	getchar();
	return 0;
}

多重指针–字符串

#include<stdio.h>
#include<string.h>
//多重指针--字符串

//三级指针
void two()
{
	printf("三级指针:\\n");
	char *a="hello world";
	char **p=&a,***pp=&p;
	printf("c=%c a=%s self-address=%p\\n",*a,a,&a);
	//char **p=&a=a的地址  根本没有存储"hello world"的地址,不能使用 %s p
	printf("a=%s address=%p self-address=%p\\n",a,p,&p);
	printf("a=%s address=%p self-address=%p\\n",a,pp,&pp);
}



int main()
{
	two();
	
	getchar();
	return 0;
}