Question

我是一名涉及Java的网络开发人员（再次），我遇到了麻烦。

基本上，我有一个超类Employee，它有两个扩展它的子类，叫做Management和Programmer。 Employee类包含一个数组employees，它基本上是一个Employee对象数组。

以下是两个类（Employee和Management）和最终主要方法的重要摘要。我将在底部解释输出。

public class **Employee** {

   private static String firstName;
   protected static int MAXEMPLOYEES = 5;
   protected Employee[] employees = new Employee[MAXEMPLOYEES];
   protected int totEmployees = 0;

   public Employee(String first) {
       setFirstName(first);
   }

   public void setFirstName(String str){
       firstName = str;
   }

   public String getFirstName(){
       return firstName;
   }

    public boolean addEmployee(String fname) {
       boolean added = false;
       if (totEmployees < MAXEMPLOYEES) {
           Employee empl = new Employee(fname);
           employees[totEmployees] = empl;
           added = true;
           totEmployees++;
       }
       return added;
   }

}

public class **Management** extends **Employee** {
    private String title = "Project Manager";

    public Management(String fname, String t){
        super(fname);
        title = t;
    }

    public boolean addManagement(String fname, String t){
        boolean added = false;

        if (totEmployees < MAXEMPLOYEES) {
            employees[totEmployees] = new Management(fname, t);
            added = true;
            totEmployees++;
        }
        return added;
    }
}

-------------------------------------
package employee;

public class EmployeeApplication {

    public static void main(String[] args) {
        Employee[] empl = new Employee[3];
        empl[0] = new Employee("Kyle");
        empl[1] = new Management("Sheree", "Director");

        System.out.println(empl[0].getFirstName());
    }
}

现在，我希望系统打印出“Kyle”，但它打印出“Sheree”。任何想法???

Answer 1

private static String firstName;

您将firstName设为静态，这意味着所有实例共享相同的名称。您需要删除静态修饰符，以便不同的Employees具有不同的名称。您还需要将私有访问修饰符更改为protected，以便子类继承该字段。

Answer 2

private String firstName;

删除static;

Kyle被Sheree覆盖，这就是你获得输出的原因

Java子类最后一个实例覆盖值

2 个答案: