C语言二级指针复习

Posted 2022-02-12 一只小阿大:)

我前两天没更是搞了一个自动化的工具，因为我们公司卷起来了，周报要PPT形式提交，我搞了个提取execel表格数据转ppt形成表格的一个玩意，我继续维护我师傅代码，新来的老哥看不懂一个二级指针，他试了老崩溃，我试了也崩溃，发现好久没写指针真的会忘，但最主要的指针是存放地址的变量即可。

所以我重新学了下指针（花了半个小时），写下此文章防止以后我忘记

#include "stdio.h"
#include "stdlib.h"

int Create(char *Name, int Age)

	printf("Name = %s,Age = %d\\n",Name ,Age);
	Name = "zhangsan";
	Age  = 21;
	
	printf("Name = %s,Age = %d\\n",Name ,Age);
	return 1;


typedef struct OD_Test

    char *Name;
	int   Age;
	int   (*Create)(char *Name, int Age);
 OD_Test;

OD_Test *HostTest = NULL;
OD_Test **HostTest2 = NULL;

int main()

	printf("Start \\n");
	
	OD_Test *HostTest = (OD_Test *)malloc(sizeof(OD_Test));
	HostTest->Name = "zhangsan";
	printf("Name = %s\\n",HostTest->Name);
	printf("HostTestAddress = %p\\n",HostTest);
	printf("HostTestAddress = %x\\n",HostTest);
	HostTest->Create = Create;
	int a = HostTest->Create("wangwu",25);
	printf("a = %d\\n",a);
	printf("end \\n");
	/*
	int a = 1;
	int *p1 = &a;
	int **p2 = &p1;
	
	printf("%d %d\\n",*p1,**p2);
	printf("a Address = %p\\n",&a);
	printf("p1 Address = %p\\n",&(*p1));
	printf("p2 Address = %p\\n",&(**p2));
	*/
	printf("Start \\n");
	OD_Test **HostTest2 = (OD_Test **)malloc(sizeof(OD_Test*));
	*HostTest2 = HostTest;
	printf("%s\\n",(*HostTest2)->Name);
	
	printf("end \\n");
	

//	free(HostTest);
	return 0;