大家好,这里是国中之林!
❥前些天发现了一个巨牛的人工智能学习网站，通俗易懂，风趣幽默，忍不住分享一下给大家。点击跳转到网站。有兴趣的可以点点进去看看←

问题:

解答:
main.cpp

#include <iostream>
#include "Cow.h"
using namespace std;int main()
{Cow c1;Cow c2("老母牛", "喝奶", 200);Cow c3(c2);c1 = c3;c1.ShowCow();cout << endl;c2.ShowCow();cout << endl;c3.ShowCow();cout << endl;return 0;
}

Cow.h

#pragma once
#include <iostream>
using namespace std;
class Cow
{char name[20];char* hobby;double weight;public:Cow();Cow(const char*nm,const char*ho,double wt);Cow(const Cow &c);~Cow();Cow& operator=(const Cow& c);void ShowCow()const;
};

Cow.cpp

#include "Cow.h"Cow::Cow()
{name[0] = '\0';hobby = NULL;weight = 0;
}
Cow::Cow(const char* nm, const char* ho, double wt)
{if ((strcpy_s(name, 20, nm)))cout << "复制失败原字符太长!" << endl;hobby = new char[strlen(ho)+1];strcpy_s(hobby, strlen(ho) + 1, ho);weight = wt;
}
Cow::Cow(const Cow&c)
{strcpy_s(name,20, c.name);hobby = new char[strlen(c.hobby) + 1];strcpy_s(hobby, strlen(c.hobby) + 1, c.hobby);weight = c.weight;
}
Cow::~Cow()
{delete[] hobby;
}
Cow& Cow::operator=(const Cow& c)
{if (this == &c){return *this;}if (hobby)delete[] hobby;strcpy_s(name, 20, c.name);hobby = new char[strlen(c.hobby) + 1];strcpy_s(hobby, strlen(c.hobby) + 1, c.hobby);weight = c.weight;return *this;
}
void Cow::ShowCow()const
{if (hobby == NULL){cout << "母牛的信息为空!" << endl;return;}cout << "母牛的名字为:" << name << endl;cout << "母牛的嗜好为:" << hobby << endl;cout << "母牛的体重为:" << weight << endl;
}

运行结果:

考查点:

• 默认构造函数
  
• 自定义构造函数
  
• 拷贝构造函数
  
• 赋值构造函数
  
• 动态内存分配
  

注意:

• strcpy_s复制成功的返回值为0
  

• strlen是得到字符串不带’\0’的长度,所以我们分配内存时需要加1

  

• 赋值构造函数返回的是引用用于连等
  

• 如果对象自己赋值自己就可以直接返回.如果原来指针不为空的需要清除
  

• 析构函数避免内存泄漏
  

2024年9月7日19:48:10