Question

对于这个问题，我得到了以下层次结构：基类Person，子类Employee和子类Staff和Supervisor。我需要在Employee，Staff和Supervisor类中应用方法覆盖。并且驱动程序类的主要方法需要创建Staff和Supervisor的多个对象，并显示其名称和月薪。

我在驱动程序类中构建了一个多态数组，但我无法弄清楚如何构造for循环以显示重写方法返回值旁边的数组的每个元素。我保持基础和子类非常简单：

public class Person {


void Salary(){
System.out.println("All positions are salaried");

}
}
public class Employee extends Person {

void Salary(){
    System.out.println("Salaries vary between staff and supervisors");
}

}
public class Staff extends Employee {

public Staff(String string) {

}

void Salary() {
    System.out.println("A regular staff employee makes 3500.00 monthly");
}


}
public class Supervisor extends Employee {


public Supervisor(String string) {
}

void Salary(){
    System.out.println("Supervisors make approximately 9800.00 monthly");
}
}

这是驱动程序类，我遇到了问题：

import java.util.Arrays;

public class HRRoster {


public static void main(String[] args) {


    Person roster[] = new Person[6];  
    roster[0] = new Supervisor("James Martin");
    roster[1] = new Supervisor("William Smith");
    roster[2] = new Supervisor("Jennifer Shipman");
    roster[3] = new Staff("Brian Williams");
    roster[4] = new Staff("Carrie James");
    roster[5] = new Staff("Samantha Powers");



            for (int i=0; i < roster.length; i++){
                System.out.print(Arrays.toString(roster));
                roster[i].Salary();
            }
    }

}

现在，它的输出是数组中的所有元素加上重写的方法，每个元素都在自己的行上。我知道我在for循环中遗漏了一些荒谬的基本/简单的东西，但我不确定如何让它从这里开始工作。基本上我想列出数组的每个元素，然后执行重写方法，每个元素都在自己的行上。

Answer 1

你期待以下行为

 import java.util.Arrays;

class Person {
    String name;
    void Salary() {
        System.out.println("All positions are salaried");

    }
    public String toString(){
        return name;
    }
}

class Employee extends Person {

    void Salary() {
        System.out.println("Salaries vary between staff and supervisors");
    }
    public String toString(){
        return name;
    }

}

class Staff extends Employee {

    public Staff(String name) {
        this.name = name;
    }

    void Salary() {
        System.out.println("A regular staff employee makes 3500.00 monthly");
    }
    public String toString(){
        return name;
    }


}

class Supervisor extends Employee {

    public Supervisor(String name) {
        this.name = name;
    }

    void Salary() {
        System.out.println("Supervisors make approximately 9800.00 monthly");
    }
    public String toString(){
        return name;
    }
}

public class HRRoster {

    public static void main(String[] args) {

        Person roster[] = new Person[6];
        roster[0] = new Supervisor("James Martin");
        roster[1] = new Supervisor("William Smith");
        roster[2] = new Supervisor("Jennifer Shipman");
        roster[3] = new Staff("Brian Williams");
        roster[4] = new Staff("Carrie James");
        roster[5] = new Staff("Samantha Powers");

        for (int i = 0; i < roster.length; i++) {
            System.out.print(roster[i].toString() + "\t");
            roster[i].Salary();
        }
    }

}

在Java中打印多态数组的不同元素

1 个答案: