虚继承解决二义性问题，虚函数解决多态问题，实现简单的公司管理系统模拟

公司管理项目模拟

要求：

一个小型公司的人员信息管理系统

某小型公司，主要有四类人员：经理、技术人员、销售经理和推销员。
现在，需要存储这些人员的姓名、编号、级别、当月薪水．计算月薪总额并显示全部信息。
人员编号基数为 1000，每输入一个人员信息编号顺序加 1。

程序要有对所有人员提升级别的功能。本例中为简单起见，所有人员的初始级别均为 1
级。然后进行升级，经理升为 4 级，技术人员和销售经理升为 3 级，推销员仍为 1 级。
定义虚函数是为了允许用基类的指针来调用子类的这个函数。
定义纯虚函数是为了实现一个接口，起到一个规范的作用，规范继承这个类的程序员必须实现这个函数。

月薪计算办法是： 经理拿固定月薪 8000 元；技术人员按每小时 100 元领取月薪； 推
销员的月薪按该推销员当月销售额的 4％提成；销售经理既拿固定月薪也领取销售提成，
固定月薪为 5000 元，销售提成为所管辖部门当月销售总额的 5%。

分析：

分析各个职员的关系，可以简单画出下列的UML图。首先抽象化出基类employee，然后有技术人员，经理，销售人员，分别继承员工类。销售经理继承销售人员和经理。1.1.在第二层的继承中会发生二义性的问题，因为在经理和销售人员都有继承来自员工的姓名，年龄等变量属性，所以在此要选择虚继承，解决二义性的问题
2.2由于每个员工都要计算工资，而每个员工计算工资方式都是不一样的，所以这是一种多态行为，在父本中定义纯虚函数，从而在子类中去实现各个功能，从而实现了多态

具体实现

1.创建父类employee

#ifndef EMPLOYEE_H
#define EMPLOYEE_H
#include
#include
using namespace std;


class Employee
{
public:
  Employee();
  ~Employee();
  virtual void display()=0;
  virtual void getSalary()=0;
  virtual void getLeavel(int l=1)=0;
  virtual void init()=0;
protected:
  string name;
  int age;
  char sex;
  float salary;
  int leavel;
  static int startNum;
  int num;
};
#endif // EMPLOYEE_H
//.cpp文件 类成员的实现
#include "employee.h"
int Employee::startNum=1000;
Employee::Employee()
{

}

Employee::~Employee()
{

}

2.创建各个子类technician

#ifndef TECHNICIAN_H
#define TECHNICIAN_H

#include"employee.h"
class Technician:public Employee
{
public:
  Technician();
  ~Technician();
  virtual void display();
  virtual void getSalary();
  virtual void getLeavel(int l=1);
  virtual void init();
  void setParaments();
private:
  float hour;
  float oneHourSalary;
};

#endif // TECHNICIAN_H
//.cpp 文件 类的实现
#include "technician.h"
#include
using namespace std;
Technician::Technician()
{

}
Technician::~Technician()
{

}
void Technician::display()
 {
  cout<<"name:"<<this->name<<endl;
  cout<<"sex:"<<this->sex<<endl;
  cout<<"age:"<<this->age<<endl;
  cout<<"Number:"<<this->num<<endl;
  cout<<"salary:"<<this->salary<<endl;
  cout<<"leavel"<<this->leavel<<endl;
 }
 void Technician::getSalary()
 {
   setParaments();
   this->salary = this->hour*this->oneHourSalary;
 }
 void Technician::getLeavel(int l)
 {
   this->leavel = l;
 }
 void Technician::init()
 {
   cout<<"please input your name:";
   cin>>this->name;
   cout<<"please input your age:";
   cin>>this->age;
   cout<<"please input your sex:";
   cin>>this->sex;
   cout<<"please input your working time:";
   cin>>this->hour;
   num = this->startNum++;
 }
 void Technician::setParaments()
 {
   this->oneHourSalary =100;
 }

3.salesMan

#ifndef SALESMAN_H
#define SALESMAN_H

#include"employee.h"
class SalesMan:public virtual Employee
{
public:
  SalesMan();
   ~SalesMan();
  virtual void display();
  virtual void getSalary();
  virtual void getLeavel(int l=1);
  virtual void init();
protected:
  float salesCount;
  float percent;
};

#endif // SALESMAN_H
//.cpp 文件 类的实现
#include "salesman.h"
#include
using namespace std;

SalesMan::SalesMan()
{

}
SalesMan::~SalesMan()
{
}
 void SalesMan::display()
 {
   cout<<"name:"<<this->name<<endl;
   cout<<"sex:"<<this->sex<<endl;
   cout<<"age:"<<this->age<<endl;
   cout<<"Number:"<<this->num<<endl;

   cout<<"salary:"<<this->salary<<endl;
   cout<<"leavel:"<<this->leavel<<endl;
 }
 void SalesMan::getSalary()
 {
   percent =0.03;
   this->salary = this->salesCount*percent;
 }
 void SalesMan::getLeavel(int l)
 {
   this->leavel = l;
 }
 void SalesMan::init(){
   cout<<"please input your name:";
   cin>>this->name;
   cout<<"please input your age:";
   cin>>this->age;
   cout<<"please input your sex:";
   cin>>this->sex;
   cout<<"please input your sale account:";
   cin>>this->salesCount;
   this->num = this->startNum++;

 }

4.manager

#define MANAGER_H

#include"employee.h"
class Manager:public virtual Employee
{
public:
  Manager();
  ~Manager();
  virtual void init();
  virtual void display();
  virtual void getSalary();
  virtual void getLeavel(int l=1);
protected:
  float fixSalary;

};

#endif // MANAGER_H

//.cpp
#include "manager.h"
#include
using namespace std;
Manager::Manager()
{

}
Manager::~Manager()
{

}
void Manager::init()
{
  cout<<"please input your name:";
  cin>>this->name;
  cout<<"please input your age:";
  cin>>this->age;
  cout<<"please input your sex:";
  cin>>this->sex;
  this->num=this->startNum++;

}
 void Manager::display()
 {
   cout<<"name:"<name<sex<age<num<salary<leavel<fixSalary=8000;
   this->salary = this->fixSalary;
 }
 void Manager::getLeavel(int l)
 {
  this->leavel=l;
 }

5.salesManager

#ifndef SALESMANAGER_H
#define SALESMANAGER_H
#include"salesman.h"
#include"manager.h"


class SalesManager:public Manager,public SalesMan
{
public:
  SalesManager();
  ~SalesManager();
  virtual void init();
  virtual void display();
  virtual void getSalary();
  virtual void getLeavel(int l=1);
};

#endif // SALESMANAGER_H
//.cpp
#include "salesmanager.h"
#include
using namespace std;
SalesManager::SalesManager()
{

}
SalesManager::~SalesManager()
{
}
 void SalesManager::init()
 {
   cout<<"please input your name:";
   cin>>this->name;
   cout<<"please input your age:";
   cin>>this->age;
   cout<<"please input your sex:";
   cin>>this->sex;
   cout<<"please input your sales account:";
   cin>>this->salesCount;
   this->num=this->startNum;
 }
 void SalesManager::display()
 {
   cout<<"name:"<<this->name<<endl;
   cout<<"sex:"<<this->sex<<endl;
   cout<<"age:"<<this->age<<endl;
   cout<<"Number:"<<this->num<<endl;

   cout<<"salary:"<<this->salary<<endl;
   cout<<"leavel:"<<this->leavel<<endl;
 }
 void SalesManager::getSalary()
 {
   this->fixSalary=5000;
   this->percent =0.02;
   salary = this->salesCount*this->percent+this->fixSalary;
 }
 void SalesManager::getLeavel(int l)
 {
   this->leavel = l;
 }

6.主函数

#include 
#include"manager.h"
#include"employee.h"
#include"technician.h"
#include"salesman.h"
#include"salesmanager.h"
using namespace std;

int main()
{
  Employee *emp[]= {new Technician,new Manager,new SalesMan,new SalesManager};
  for(int i=0;i<(sizeof(emp)/sizeof(emp[1]));i++)
    {
      emp[i]->init();
      emp[i]->getSalary();
      emp[i]->getLeavel(2);
      emp[i]->display();
    }
  return 0;
}

小结

1.虚函数主要实现面向对象三大特点中的多态，而虚继承主要解决多继承中二义性问题或者叫做三角问题，钻石问题。
2.此blog仅仅作为学习记录内容，希望能对你有一定的帮助。该篇主要是C++的入门。
3.如有任何问题，请多多指正。