cpp: point

®Geovin Du Dream Park™ / 2023-05-14 / 原文

// ConsoleStructSimpleApp.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include <fstream>//文件操作
#include <sstream>//int转string
#include <iomanip>//cout格式化输出 setw()
#include <stdlib.h>
#include "GeovinDu.h"


using namespace std;
using namespace DuStructSimple;


//#pragma pack(2)
/// <summary>
/// 
/// </summary>
enum weekdayname
{

	/// <summary>
	/// 
	/// </summary>
	SUN=1,
	/// <summary>
	/// 
	/// </summary>
	MON=2, 
	/// <summary>
	/// 
	/// </summary>
	TUE=3, 
	/// <summary>
	/// 
	/// </summary>
	WED=4, 
	/// <summary>
	/// 
	/// </summary>
	THU=5, 
	/// <summary>
	/// 
	/// </summary>
	FRI=6, 
	/// <summary>
	/// 
	/// </summary>
	SAT=7

};

/// <summary>
/// 
/// </summary>
enum color
{
	red = 5,
	blue,
	green
};

union person
{
	int age;
	char name[256];
	char sex[2];

};

union person2
{
	int age;
	char name;
	char sex;

}du;


void func(int** pp)
{
	*pp= new int(3);
	//*pp = 40;
	cout << "pp=" << pp << ",*pp=" << *pp <<",**pp=" << **pp<< endl;

}

void func2(int* pp)
{
	*pp = 3;
	cout << "pp2=" << pp << ",*pp2=" << *pp << endl;

}

int main()
{

	int* dup=0;
	func(&dup);
	cout << "p==" << dup << ",*p==" << *dup << endl;
	//2
	cout << "**************2*************" << endl;
	int dup2 = 1;
	func2(&dup2);
	cout << "p2==" << dup << ",&p2==" << &dup << endl;

	int a = 10;
	cout << "&a=" << &a << endl;
	int* p = &a;
	cout << "p=" << p <<",&p="<<&p<<",*p="<<*p << endl;
	int** j = &p;
	cout << "j=" << j << ",&j=" << &j << endl;
	cout << "*j=" << *j << endl;
	cout<<",**j="<<**j<< endl;


	//person per;
	//per.age = 30;
	////per.name = "g";
	////per.sex = "m";

	//cout << "person内存：" << sizeof(person) << endl;
	//cout << "person2 内存：" << sizeof(person2) << endl;


	//cout << "person sex内存 " << sizeof(per.sex) << endl;

	//cout << "person2 sex内存 " << sizeof(du.sex) << endl;
	////地址相同：
	//cout << "per.name=" << &per.name << endl;
	//cout << "per.age=" << &per.age << endl;
	//cout << "per=" << &per << endl;

   // std::cout << "Hello World!涂聚文 Geovin Du\n";

	//int num;
	//cout << "输入5-7(红，蓝，绿）:" << endl;
	//cin >> num;
	//switch (num)
	//{
	//case 5:
	//	cout << "红色" << endl;
	//	break;
	//case 6:
	//	cout << "蓝色" << endl;
	//	break;
	//case 7:
	//	cout << "绿色" << endl;
	//	break;
	//default:
	//	cout << "错误！" << endl;
	//	break;
	//}


	//cout << "枚举类型：" << endl;
	//cout << SUN <<","<<MON<<","<<TUE<<"," << WED <<","<<THU<<","<<FRI<<","<<SAT<< endl;

	//enum weekdayname day;
	//day = FRI;
	//cout << day << endl;

	//GeovinDu geovin;

	//
	//geovin.DisplayStructSize();

	//geovin.displayStudent();
	// 无用
	//geovin.dispalyStructDemo();
	// 
	// 
	//geovin.dsipalyFuntion();

	//geovin.dipslayStructCustomer();

	system("pause");
	return 0;

}

// 运行程序: Ctrl + F5 或调试 >“开始执行(不调试)”菜单
// 调试程序: F5 或调试 >“开始调试”菜单

// 入门使用技巧: 
//   1. 使用解决方案资源管理器窗口添加/管理文件
//   2. 使用团队资源管理器窗口连接到源代码管理
//   3. 使用输出窗口查看生成输出和其他消息
//   4. 使用错误列表窗口查看错误
//   5. 转到“项目”>“添加新项”以创建新的代码文件，或转到“项目”>“添加现有项”以将现有代码文件添加到项目
//   6. 将来，若要再次打开此项目，请转到“文件”>“打开”>“项目”并选择 .sln 文件

// ConsoleStructSimpleApp.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include <fstream>//文件操作
#include <sstream>//int转string
#include <iomanip>//cout格式化输出 setw()
#include <stdlib.h>
#include "GeovinDu.h"


using namespace std;
using namespace DuStructSimple;


//#pragma pack(2)
/// <summary>
/// 
/// </summary>
enum weekdayname
{

	/// <summary>
	/// 
	/// </summary>
	SUN=1,
	/// <summary>
	/// 
	/// </summary>
	MON=2, 
	/// <summary>
	/// 
	/// </summary>
	TUE=3, 
	/// <summary>
	/// 
	/// </summary>
	WED=4, 
	/// <summary>
	/// 
	/// </summary>
	THU=5, 
	/// <summary>
	/// 
	/// </summary>
	FRI=6, 
	/// <summary>
	/// 
	/// </summary>
	SAT=7

};

/// <summary>
/// 
/// </summary>
enum color
{
	red = 5,
	blue,
	green
};

union person
{
	int age;
	char name[256];
	char sex[2];

};

union person2
{
	int age;
	char name;
	char sex;

}du;

/// <summary>
/// 二级指针
/// </summary>
/// <param name="pp">形参</param>
void func(int** pp)
{
	int* p = 0;
	int** dup = &p;
	*dup = new int(3);

	cout << "&pp=" << &pp << endl;
	cout << "*pp=" << *pp << endl;
	cout << "**pp=" << **pp << endl;

	*pp= new int(3);
	//*pp = 40;
	cout << "pp=" << pp << ",*pp=" << *pp <<",**pp=" << **pp<<",&pp="<<&pp<< endl;

	//*pp指向p, pp指向new, &pp指向自已

}
/// <summary>
/// 
/// </summary>
/// <param name="pp"></param>
void func2(int* pp)
{
	*pp = 3;
	cout << "pp2=" << pp << ",*pp2=" << *pp << endl;

}

int main()
{

	//int* dup=0;
	//func(&dup);
	//cout << "p==" << dup << ",*p==" << *dup << endl;
	//2
	cout << "**************2*************" << endl;
	int dup2 = 10;
	cout << "dup2=" << &dup2 << endl;
	int* dupp = &dup2;
	cout << "dupp=" << &dupp << endl;
	func(&dupp);
	cout << "p2==" << dupp << ",&p2==" << &dupp <<",*dupp="<<*dupp << endl;

	//3
	cout << "3***********" << endl;
	int kk = 20;
	int* dukk = &kk;
	func2(dukk);

	cout << "4************" << endl;

	int a = 10;
	cout << "&a=" << &a << endl;
	int* p = &a;
	cout << "p=" << p <<",&p="<<&p<<",*p="<<*p << endl;
	int** j = &p;
	cout << "j=" << j << ",&j=" << &j << endl;
	cout << "*j=" << *j << endl;
	cout<<",**j="<<**j<< endl;


	//person per;
	//per.age = 30;
	////per.name = "g";
	////per.sex = "m";

	//cout << "person内存：" << sizeof(person) << endl;
	//cout << "person2 内存：" << sizeof(person2) << endl;


	//cout << "person sex内存 " << sizeof(per.sex) << endl;

	//cout << "person2 sex内存 " << sizeof(du.sex) << endl;
	////地址相同：
	//cout << "per.name=" << &per.name << endl;
	//cout << "per.age=" << &per.age << endl;
	//cout << "per=" << &per << endl;

   // std::cout << "Hello World!涂聚文 Geovin Du\n";

	//int num;
	//cout << "输入5-7(红，蓝，绿）:" << endl;
	//cin >> num;
	//switch (num)
	//{
	//case 5:
	//	cout << "红色" << endl;
	//	break;
	//case 6:
	//	cout << "蓝色" << endl;
	//	break;
	//case 7:
	//	cout << "绿色" << endl;
	//	break;
	//default:
	//	cout << "错误！" << endl;
	//	break;
	//}


	//cout << "枚举类型：" << endl;
	//cout << SUN <<","<<MON<<","<<TUE<<"," << WED <<","<<THU<<","<<FRI<<","<<SAT<< endl;

	//enum weekdayname day;
	//day = FRI;
	//cout << day << endl;

	//GeovinDu geovin;

	//
	//geovin.DisplayStructSize();

	//geovin.displayStudent();
	// 无用
	//geovin.dispalyStructDemo();
	// 
	// 
	//geovin.dsipalyFuntion();

	//geovin.dipslayStructCustomer();

	system("pause");
	return 0;

}

// 运行程序: Ctrl + F5 或调试 >“开始执行(不调试)”菜单
// 调试程序: F5 或调试 >“开始调试”菜单

// 入门使用技巧: 
//   1. 使用解决方案资源管理器窗口添加/管理文件
//   2. 使用团队资源管理器窗口连接到源代码管理
//   3. 使用输出窗口查看生成输出和其他消息
//   4. 使用错误列表窗口查看错误
//   5. 转到“项目”>“添加新项”以创建新的代码文件，或转到“项目”>“添加现有项”以将现有代码文件添加到项目
//   6. 将来，若要再次打开此项目，请转到“文件”>“打开”>“项目”并选择 .sln 文件

/// <summary>
/// 指针
/// </summary>
/// <param name="pp">形参</param>
void func3(int* pp)
{
	int* p = 0;
	int** dup = &p;
	*dup = new int(3);

	cout << "&pp=" << &pp << endl;
	cout << "*pp=" << *pp << endl;
	//cout << "**pp=" << **pp << endl;

	pp = new int(3);
	//*pp = new int(3);
	//*pp = 40;
	//cout << "pp=" << pp << ",*pp=" << *pp << ",**pp=" << **pp << ",&pp=" << &pp << endl;
	cout << "pp=" << pp << ",*pp=" << *pp << ",&pp=" << &pp << endl;
	//*pp指向p, pp指向new, &pp指向自已

}

/// <summary>
/// 二级指针
/// </summary>
/// <param name="pp">形参</param>
int func(int** pp)
{
	int* p = 0;
	int** dup = &p;
	*dup = new int(3);

	cout << "&pp=" << &pp << endl;
	cout << "*pp=" << *pp << endl;
	cout << "**pp=" << **pp << endl;

	*pp= new int(3);
	//*pp = 40;
	cout << "pp=" << pp << ",*pp=" << *pp <<",**pp=" << **pp<<",&pp="<<&pp<< endl;

	//*pp指向p, pp指向new, &pp指向自已
	return **pp;

}
/// <summary>
/// 指针
/// </summary>
/// <param name="pp">形参</param>
int func3(int* pp)
{
	int* p = 0;
	int** dup = &p;
	*dup = new int(3);

	cout << "&pp=" << &pp << endl;
	cout << "*pp=" << *pp << endl;
	//cout << "**pp=" << **pp << endl;

	pp = new int(3);
	//*pp = new int(3);
	//*pp = 40;
	//cout << "pp=" << pp << ",*pp=" << *pp << ",**pp=" << **pp << ",&pp=" << &pp << endl;
	cout << "pp=" << pp << ",*pp=" << *pp << ",&pp=" << &pp << endl;
	//*pp指向p, pp指向new, &pp指向自已

	return *pp;

}
/// <summary>
/// 
/// </summary>
/// <param name="pp"></param>
int func2(int* pp)
{
	*pp = 3;
	cout << "pp2=" << pp << ",*pp2=" << *pp << endl;
	return *pp;

}