// Employee.java
// 抽象類Employee

public abstract class Employee {
   private String firstName;
   private String lastName;

   // 構造函數
   public Employee( String first, String last )
   {
      firstName = first;
      lastName = last;
   }
   
   // 返回姓
   public String getFirstName() { return firstName; }

   // 返回名
   public String getLastName() { return lastName; }

   public String toString()
      { return firstName + ' ' + lastName; }

   // Employee抽象方法earnings();
   //將被其每個子類以實例繼承 
   public abstract double earnings(); 
}