实验三 继承，上转型对象 之 HardWork.java

（二）HardWork.java

abstract class Employee

{

   public abstract double earnings( );

}

class YearWorker extends Employee

{

public double earnings() {

return 1200000.00;

}

}

class MonthWorker extends Employee

{

public double earnings() {

return 120000.00;

}

}

class WeekWorker extends Employee

{

public double earnings() {

return 30000.00;

}

}

class Company

{

   Employee[] employee;

   double salaries=0;

   Company(Employee[] employee) {

      this.employee=employee;

   }

   public double salariesPay() {

      salaries=0;

      for (Employee e : employee) {

      salaries +=e.earnings();

      }

      return salaries;

   }    

}

public class HardWork

{

   public static void main(String args[ ])

   {

      Employee[] employee=new Employee[20];

      for(int i=0;i<employee.length;i++)

       {  if(i%3==0)

             employee[i]=new WeekWorker( );

           else if(i%3==1)

             employee[i]=new MonthWorker( );

           else if(i%3==2)

             employee[i]=new YearWorker( );

       } 

     Company company=new Company(employee);

     System.out.println("公司年工资总额:"+company.salariesPay());

   }

}

运行结果：