C++_day6 - 技术栈

思维导图：

2试编程

封装一个动物的基类，类中有私有成员: 姓名，颜色，指针成员年纪

再封装一个狗这样类，共有继承于动物类，自己拓展的私有成员有:指针成员:腿的个数(整型 int count)，共有成员函数：会叫: void speak()

要求:分别完成基类和派生类中的:构造函数、析构函数、拷贝构造函数、拷贝赋值函数

Dog d1;

Dog d2(.....);

Dog d3(d2);

d1 = d3,

cpp 复制代码

#include <iostream>

using namespace std;

class Animal
{
private:
    string name;
    string color;
    int *age;
protected:

public:
    Animal()
    {
        cout << "Animal::无参构造函数" << endl;
    }
    Animal(string name,string color,int age):name(name),color(color),age(new int(age))
    {
        cout << "Animal::有参构造函数" << endl;
    }
    ~Animal()
    {
        cout << "Animal::析构函数" << endl;
        delete age;
    }
    Animal(const Animal &other):name(other.name),color(other.color),age(new int(*other.age))
    {
        cout << "Animal::拷贝构造函数" << endl;
    }
    Animal &operator=(const Animal &other)
    {
        if(this != &other)
        {
            name = other.name;
            color = other.color;
            age = new int(*other.age);
        }
        cout << "Animal::拷贝赋值函数" << endl;
        return *this;
    }
    void show()
    {
        cout << name << " " << color << " " << *age << " ";
    }
};
class Dog:public Animal
{
private:
    int *count;
public:
    void speak()
    {
        cout << "汪汪汪~" << endl;
    }
    Dog()
    {
        cout << "Dog::无参构造函数" << endl;
    }
    Dog(string name,string color,int age,int count):Animal(name,color,age),count(new int(count))
    {
        cout << "Dog::有参构造函数" << endl;
    }
    ~Dog()
    {
        cout << "Dog::析构函数" << endl;
        delete count;
    }
    Dog(const Dog &other):Animal(other),count(new int(*other.count))
    {
        cout << "Dog::拷贝构造函数" << endl;
    }
    Dog &operator=(const Dog &other)
    {
        if(this != &other)
        {
            Animal::operator=(other);
            count = new int(*other.count);
        }
        cout << "Dog::拷贝赋值函数" << endl;
        return *this;
    }
    void show()
    {
        Animal::show();
        cout << *count << endl;
    }
};
int main()
{
    Dog d1;
    Dog d2("小黑","黑色",5,4);
    d2.show();
    Dog d3(d2);
    d3.show();
    d1=d3;
    d1.show();
    return 0;
}

运行结果：

3.编程题

以下是一个简单的比喻，将多态概念与生活中的实际情况相联系:

比喻:动物园的讲解员和动物表演

想象一下你去了一家动物园，看到了许多不同种类的动物，如狮子、大象、猴子等。现在，动物园里有一位讲解员，他会为每种动物表演做简单的介绍。

在这个场景中，我们可以将动物比作是不同的类，而每种动物表演则是类中的函数。而讲解员则是一个基类，他可以根据每种动物的特点和表演，进行相应的介绍。

具体过程如下

定义一个基类Animal，其中有一个虚函数perform ()，用于在子类中实现不同的表演行为

cpp 复制代码

#include <iostream>

using namespace std;

class Animal
{
private:
    string name;
    string color;
    int *age;
protected:

public:
    Animal()
    {
        cout << "Animal::无参构造函数" << endl;
    }
    Animal(string name,string color,int age):name(name),color(color),age(new int(age))
    {
        cout << "Animal::有参构造函数" << endl;
    }
    ~Animal()
    {
        cout << "Animal::析构函数" << endl;
        delete age;
    }
    Animal(const Animal &other):name(other.name),color(other.color),age(new int(*other.age))
    {
        cout << "Animal::拷贝构造函数" << endl;
    }
    Animal &operator=(const Animal &other)
    {
        if(this != &other)
        {
            name = other.name;
            color = other.color;
            age = new int(*other.age);
        }
        cout << "Animal::拷贝赋值函数" << endl;
        return *this;
    }
    virtual void perform() = 0;
    void show()
    {
        cout << name << " " << color << " " << *age << " ";
    }
};
class Elephant:public Animal
{
private:
    int *count;
public:
    void perform()
    {
        cout << "喷水  吃香蕉" << endl;
    }
    Elephant()
    {
        cout << "Elephant::无参构造函数" << endl;
    }
    Elephant(string name,string color,int age,int count):Animal(name,color,age),count(new int(count))
    {
        cout << "Elephant::有参构造函数" << endl;
    }
    ~Elephant()
    {
        cout << "Elephant::析构函数" << endl;
        delete count;
    }
    Elephant(const Elephant &other):Animal(other),count(new int(*other.count))
    {
        cout << "Elephant::拷贝构造函数" << endl;
    }
    Elephant &operator=(const Elephant &other)
    {
        if(this != &other)
        {
            Animal::operator=(other);
            count = new int(*other.count);
        }
        cout << "Dog::拷贝赋值函数" << endl;
        return *this;
    }
    void show()
    {
        Animal::show();
        cout << *count << endl;
    }
};
class Lion:public Animal
{
private:
    int *count;
public:
    void perform()
    {
        cout << "钻火圈" << endl;
    }
    Lion()
    {
        cout << "Lion::无参构造函数" << endl;
    }
    Lion(string name,string color,int age,int count):Animal(name,color,age),count(new int(count))
    {
        cout << "Lion::有参构造函数" << endl;
    }
    ~Lion()
    {
        cout << "Lion::析构函数" << endl;
        delete count;
    }
    Lion(const Lion &other):Animal(other),count(new int(*other.count))
    {
        cout << "Lion::拷贝构造函数" << endl;
    }
    Lion &operator=(const Lion &other)
    {
        if(this != &other)
        {
            Animal::operator=(other);
            count = new int(*other.count);
        }
        cout << "Dog::拷贝赋值函数" << endl;
        return *this;
    }
    void show()
    {
        Animal::show();
        cout << *count << endl;
    }
};
int main()
{
    Elephant e1("大象","五彩",6,4);
    Lion l1("狮子","棕黄色",4,4);
    e1.perform();
    l1.perform();
    return 0;
}