类和对象小练习

项目树

代码部分

main.cpp

#include <iostream>
#include <Landowner_v4.h>//如果要使用类,那么必须包含类的头文件
using namespace std;

int main()
{//构造函数的重载规则与普通函数相同
    Landowner_v4 owner1;
    cout << "***************************\n";
    Landowner_v4 owner2("改改","黑马");//记得加双引号哦
    owner2.show_info();
    cout << "***************************\n";
    Landowner_v4 owner3(25);
    //Landowner_v4 owner3 = 25;//如果构造函数中,有且仅有一个参数,则可以写成Landowner_v4 owner3 = 25;
    cout << "***************************\n";
    //使用指针的方法访问成员变量
    Landowner_v4* owner4; //定义指向结构体类型Landowner_v4的数据的指针变量owner4
    owner4 = new Landowner_v4("红红","牛掰");//给指针分配内存的同时调用构造函数
            //用new运算符开辟一个存放Landowner_v4型数据的空间
    owner4 -> show_info(); //向结构体变量的方法
    delete owner4; //撤销该空间
    return 0;
}

C++中new的用法

Landowner_v4.h

#ifndef LANDOWNER_V4_H
#define LANDOWNER_V4_H
#include <iostream>
#include <string>
using namespace std;

class Landowner_v4
{
    public:
        Landowner_v4();
        Landowner_v4(string, string);
        Landowner_v4(int);
        void show_info();
        virtual ~Landowner_v4();

        string GetName() { return m_Name; }
        void SetName(string val) { m_Name = val; }
        string GetDesc() { return m_Desc; }
        void SetDesc(string val) { m_Desc = val; }
        int GetAge() { return m_Age; }
        void SetAge(int val) { m_Age = val; }

    protected:

    private:
        string m_Name;
        string m_Desc;
        int m_Age;
};
#endif // LANDOWNER_V4_H

Landowner_v4.cpp

#include "Landowner_v4.h"
#include <iostream>
#include <string>
using namespace std;

Landowner_v4::Landowner_v4()
{
    //ctor
    cout << "调用的是默认构造(即无参构造)Landowner_v4()\n" ;

}

Landowner_v4::Landowner_v4(string name, string desc)
{
    cout << "调用的是带参构造函数Landowner_v4(string name, string desc)\n" ;
    m_Name = name;//等价写法SetName(name);
    m_Desc = desc;
}
Landowner_v4::Landowner_v4(int age)
{
   cout << "调用的是带参构造函数Landowner_v4(int age)\n" ;
   SetAge(age); //等价写法m_Age = age;
}

void Landowner_v4::show_info()
{
    cout << m_Desc << m_Name << endl;
}

Landowner_v4::~Landowner_v4()
{
    //dtor
}

运行结果