C++的多态例子

  1 #define _CRT_SECURE_NO_WARNINGS
  2 #include<iostream>
  3 #include<string>
  4 using namespace std;
  5 
  6 //创建一个抽象类
  7 class Employee
  8 {
  9 public:
 10     Employee()
 11     {
 12         inum++;                //这里是要点： 当时没有想出来，在写一个变量来接收静态变量的变化值
 13         mID = inum;            //可以做到当每增加一个员工，它的 ID 会自动 加一。
 14         mName = "NoDefined";
 15         mSalary = 0.0;
 16     }
 17     
 18     virtual void GetPay() = 0;    //不同的计算工资方法；
 19     virtual void Show()            //在基类中实现出来，如果内容相同，子类就不用再实现了。当时没想到
 20     {
 21         cout << "姓名:" << mName << " ID:" << mID << " 工资:" << mSalary << endl;
 22     }
 23     virtual ~Employee(){ }            //基类的析构函数一般写成虚继承，可以做到把基类和子类对象一起析构
 24 protected:
 25     int mID;
 26     string mName;
 27     double mSalary;
 28     static int inum;
 29 };
 30 int Employee::inum = 1000;
 31 
 32 //经理
 33 class Manager : virtual public Employee
 34 {
 35 public:
 36     Manager(){}
 37     Manager(string name)
 38     {
 39         mName = name;
 40         base = 8000;
 41     }
 42     
 43     virtual void GetPay()
 44     {
 45         mSalary = base;
 46     }
 47     
 48 protected:
 49     double base;
 50 };
 51 //技术人员
 52 class Technician : public Employee
 53 {
 54 public:
 55     Technician(string name, int hour = 0)
 56     {
 57         mName = name;
 58         mHour = hour;
 59     }
 60     
 61     virtual void GetPay()
 62     {
 63         mSalary = mHour * 100;
 64     }
 65 protected:
 66     int mHour;
 67 };
 68 
 69 //销售人员
 70 class SalesMan : virtual public Employee
 71 {
 72 public:
 73     SalesMan(){}
 74     SalesMan(string name, double count = 0)
 75     {
 76         mName = name;
 77         mCount = count;
 78     }
 79     
 80     virtual void GetPay()
 81     {
 82         mSalary = mCount * 4 / 100;
 83     }
 84 protected:
 85     double mCount;
 86 };
 87 
 88 //销售经理
 89 class SalesManager : public SalesMan, public Manager        //此处用了虚继承，解决了二义性，也是重点。
 90 {
 91 public:
 92     SalesManager()
 93     {
 94         
 95     }
 96     SalesManager(string name, double count)
 97     {
 98         base = 5000;
 99         mName = name;
100         mCount = count;
101     }
102     
103     virtual void GetPay()
104     {
105         mSalary = base + mCount * 5 / 100;
106     }
107 };
108 
109 void printInfo(Employee& emp)
110 {
111     emp.GetPay();
112     emp.Show();
113 }
114 void test03()
115 {
116     Manager m1("xiaoyong");
117     Technician t1("xiaoming", 200);
118     SalesMan s1("xiaohong", 80000);
119     SalesManager sm1("xiaoyong", 100000);
120 
121     printInfo(m1);
122     printInfo(t1);
123     printInfo(s1);
124     printInfo(sm1);
125 }
126 
127 int main()
128 {
129 
130     test03();
131 
132     system("pause");
133     return EXIT_SUCCESS;
134 }

 1 class person{
 2 public:
 3 person(int num = 0) : Age(num) "初始化列表"
 4 { }    
 5 void show()
 6 {
 7 cout<<"Age:"<<Age<<" ID"<<ID<<" size"<<size<<endl;
 8 }
 9 private:
10 static int ID;    "在类外初始化"
11 const int Age;    "初始化列表"
12 const static int size = 100;    "在本地初始化：即定义的地方"
13 };
14 int person::ID = 30;