动物世界

1、实现Mammal类的方法

2、由Mammal类派生出Dog类，在Dog类中增加itsColor成员(COLOR类型)

3、Dog类中增加以下方法：

constructors: Dog()、Dog(int age)、Dog(int age, int weight)、Dog(int age, COLOR color)、 Dog(int age, int weight, COLOR color)、~Dog()

accessors: GetColor()、SetColor()

Other methods: WagTail()、BegForFood() ，并实现以上这些方法 。

提示：类似Speak()、WagTail()这些动作，函数体可以是输出一句话。比如：Mammal is spaeking... , The Dog is Wagging its tail...

4、补充主函数的问号部分，并运行程序，检查输出是否合理。

#include<iostream>
using namespace std;
enum COLOR{ WHITE, RED, BROWN, BLACK, KHAKI };
class Mammal
{
  public:
    //constructors
    Mammal();
    Mammal(int age);
    ~Mammal();
    
    //accessors
    int GetAge() const;
    void SetAge(int);
    int GetWeight() const;
    void SetWeight(int);
    
    //Other methods 
    void Speak() const;
    void Sleep() const;   
  protected:
    int itsAge;
    int itsWeight;
};
Mammal::Mammal(){}//定义构造函数
Mammal::Mammal(int age):itsAge(age){}
Mammal::~Mammal(){}
int Mammal::GetAge() const//用于获取itsAge
{
  return itsAge;
}
void Mammal::SetAge(int age)//用于设置itsAge
{
  itsAge=age;
}
int Mammal::GetWeight() const//用于获取itsWeight
{
  return itsWeight;
}
void Mammal::SetWeight(int weight)//用于设置itsWeight
{
  itsWeight=weight;
}
void Mammal::Speak() const//成员函数
{
  cout<<"Mammal is speaking..."<<endl;
}
void Mammal::Sleep() const//成员函数
{
  cout<<"Mammal is sleeping..."<<endl;
}

class Dog:public Mammal//定义Dog类，继承Mammal类
{
private:
  COLOR itsColor;//设置颜色为私有属性，类型为枚举COLOR类型
public:
  Dog();
  Dog(int age);
  Dog(int age,int weight);
  Dog(int age,COLOR color);
  Dog(int age,int weight,COLOR color);
  ~Dog();
  COLOR GetColor();
  void SetColor(COLOR color);
  void WagTail();
  void BegForFood();
};
Dog::Dog(){}//定义构造函数
Dog::Dog(int age):Mammal(age){}//调用基类的构造函数
Dog::Dog(int age,int weight):Mammal(age)
{
  this->SetWeight(weight);
}
Dog::Dog(int age,COLOR color):Mammal(age)
{
  this->itsColor=color;
}
Dog::Dog(int age,int weight,COLOR color):Mammal(age)
{
  this->SetWeight(weight);
  this->itsColor=color;
}
Dog::~Dog(){}//定义析构函数
COLOR Dog::GetColor()//获取对象的itsColor值
{
  return itsColor;
}
void Dog::SetColor(COLOR color)//设置对象的itsCokor值
{
  itsColor=color;
}
void Dog::WagTail()//定义成员函数
{
  cout<<"The dog is wagging its tail..."<<endl;
}
void Dog::BegForFood()//定义成员函数
{
  cout<<"The dog is begging its food..."<<endl;
}
int main()
{
  Dog Fido;
  Dog Rover(5);
  Dog Buster(6, 8);
  Dog Yorkie(3, RED);
  Dog Dobbie(4, 20, KHAKI);
  Fido.Speak();
  Rover.WagTail();
  cout<<"Yorkie is "<<Yorkie.GetAge()<<" years old."<<endl;
  cout<<"Dobbie weighs "<<Dobbie.GetWeight()<<" pounds."<<endl;   
  return 0;
}

 构造函数和析构函数只声明不定义会报错