Question

我要求修改类Staff，方法是使用displaySalary()方法替换toString()方法，该方法返回要显示的所有必需信息，并在main方法中打印SOP但我甚至不知道从哪里开始，因为正如我所声明的，salary是double，我们如何使用String？我真的迷失了。如果我建议从哪里开始，那将是一种感激之情。

这是给定的代码：

class Staff {

    private String name, staffID;
    private double salary;
    private double commission;
    private int workingHours;
    private double Sales;
    public void setStaffInfo(String nm, String id, int wHour, double sale) 
    {
        name=nm;
        staffID=id;
        workingHours=wHour;
        Sales=sale;
    }

    public void calculateSalary(){
        salary = (workingHours*8);
    }

    public double displaySalary(){
        return salary;
    }

    public String displayName(){
        return name;
    }

    public String displayStaffID(){
        return staffID;
    }

    public double displayworkingHours(){
        return workingHours;
    }

    public double displaySales(){
        return Sales;

    }

    public void calculateCommission(){

        if(Sales >= 150 && Sales <= 300)
            commission= (0.05*Sales);


        else if(Sales >=301 && Sales <= 500)
            commission= (0.1*Sales);


        else if (Sales > 500)
            commission=(0.15*Sales);

        else
            commission= 0;

    }

    public double displayCommission(){
        return commission;
    }

}

这是主要方法的代码：

import java.util.Scanner;
class TestStaff {
    static Scanner scan = new Scanner(System.in);
    public static void main(String arg[]){

        Staff staff1= new Staff();


        System.out.print("Enter your name: ");
        String nm=scan.nextLine();

        System.out.print("Enter your Staff ID: ");
        String id=scan.nextLine();

        System.out.print("Enter your working hours: ");
        int wHour=scan.nextInt(); 

        System.out.print("Enter your total sales: ");
        double sale=scan.nextDouble();

        staff1.setStaffInfo(nm, id, wHour, sale);
        staff1.calculateCommission();
        staff1.calculateSalary();
        System.out.println("\nStaff Name: " + staff1.displayName());
        System.out.println("Staff ID: " + staff1.displayStaffID());
        System.out.println("Hours worked: " + staff1.displayworkingHours());
        System.out.println("Total sales: RM" +staff1.displaySales());

        double com= staff1.displayCommission();
        double sala= staff1.displaySalary();
        double total= sala+com;

        System.out.println("Salary: RM" + total);

    }
}

Answer 1

将对象放到System.out.println时，会调用该对象的toString方法。

如果你没有提供一个被覆盖的版本，那么它将打印像Staff@123f23这样的对象指针。

所以你要做的就是用你的显示逻辑重载类toString内的Staff方法。例如：

@Override
public String toString() {
    double com= staff1.displayCommission();
    double sala= staff1.displaySalary();
    double total= sala+com;

    return "Staff Name: " + staff1.displayName())
    + "\nStaff ID: " + staff1.displayStaffID())
    + "\nHours worked: " + staff1.displayworkingHours())
    + "\nTotal sales: RM" +staff1.displaySales())
    + "\nSalary: RM" + total );
}

Answer 2

只需覆盖像这样的方法

public String toString(){
      //write which field you need to show
      return Double.toString(d);
      // Here you append other column as per your need. 
}

Answer 3

替换此

System.out.println("Hours worked: " + staff1.displayworkingHours());

与

System.out.println("Hours worked: " + Double.toString(staff1.displayworkingHours()));

和这个

System.out.println("Total sales: RM" +staff1.displaySales());

带

System.out.println("Total sales: RM" + Double.toString(staff1.displaySales()));

逻辑是，首先使用toString（yourDoubleColumn）将双列转换为字符串，并使用字符串连接字符串

问我你是否仍然面临问题

如何使用toString（）方法替换显示方法？

3 个答案: