如何为方法创建一个新类？

Posted 2023-02-23

【中文标题】如何为方法创建一个新类？

【英文标题】：How to create a new class for a method?

【发布时间】：2022-01-01 16:18:56

【问题描述】：

package HargaSewaKamar;

import java.io.*;

class Main 
 public static void main (String [] args) throws IOException
  String nama="",kamar="",jenis="";
  int lama=0,tarif=0;
  
  BufferedReader br = new BufferedReader(new InputStreamReader (System.in));
  
  System.out.println("--**-- SISTEM INFORMASI PERHOTELAN --**--");
  System.out.print("Nama Pelanggan \t\t\t: ");
  nama = br.readLine();
  
  System.out.println("\nPilih Jenis Kamar");
  System.out.println("R. Reguler");
  System.out.println("S. Suite");
  System.out.println("P. President");
  System.out.print("Jenis kamar yang dipesan (R/S/P) \t: ");
  jenis = br.readLine();
  
  System.out.print("\nLama Menginap \t\t\t: ");
  lama = Integer.parseInt(br.readLine());
  
  if (jenis.equals("R"))
   tarif = lama*300000;
   kamar="Reguler";
  else if (jenis.equals("S"))
   tarif = lama*500000;
   kamar="Suite";
  else if (jenis.equals("P"))
   tarif = lama*750000;
   kamar="President";
  
  
  System.out.println("\n\n---***--- NOTA PEMBAYARAN HOTEL ---***---");
  System.out.println("Nama Pelanggan \t\t\t: " + nama);
  System.out.println("Jenis Kamar \t\t\t: " + kamar);
  System.out.println("Tarif Penginapan \t\t: Rp " + tarif + ",-");
  System.out.println("====================================================");
 

我正在为涉及酒店定价的案例研究构建一个简单的程序。 Main.java 应该是用户输入数据的地方，而 Hotel.java 是根据入住天数计算价格类别的地方。这是 Main.java，我希望将“if”方法放在 Hotel.java 中。我这样做了，但编译器一直给我 0。

这是Hotel.java

public class Hotel
public static String hitung(String jenis)

String kamar = "";
int tarif=0;
int lama=0;
  if (jenis.equals("R"))
   tarif = lama*300000;   
   kamar="Reguler";
  else if (jenis.equals("S"))
   tarif = lama*500000;
   kamar="Suite";
  else if (jenis.equals("P"))
   tarif = lama*750000;
   kamar="President";

  return kamar;

【问题讨论】：

"我这样做了，但编译器一直给我 0。"请显示不起作用的代码 - 目前您还没有向我们显示 Hotel.java，并且您的代码没有引用它。请提供minimal reproducible example。

【参考方案1】：

您需要将Hotel 类更改为其他内容。您实际上需要一个具有接受nama、jenis 和lama 的构造函数的类。在此计算kamar 和tarif 如下（我称它为HotelReservation，因为它似乎更合适）：

public class HotelReservation 
    private final String nama;
    private final String kamar;
    private final int tarif;

    public HotelReservation(String nama, String jenis, int lama)
        this.nama = nama;

        switch (jenis) 
            case "R":
                tarif = lama * 300000;
                kamar = "Reguler";
                break;
            case "S":
                tarif = lama * 500000;
                kamar = "Suite";
                break;
            case "P":
                tarif = lama * 750000;
                kamar = "President";
                break;
            default:
                tarif = 0;
                kamar = "Invalid";
                break;
        
    

    public String getNama() 
        return nama;
    

    public String getKamar() 
        return kamar;
    

    public int getTarif() 
        return tarif;
    

有了这个类，你现在可以在你的主方法中根据用户的数据创建一个新的酒店预订：

public class Main 
    public static void main (String [] args) throws IOException
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        System.out.println("--**-- SISTEM INFORMASI PERHOTELAN --**--");
        System.out.print("Nama Pelanggan \t\t\t: ");
        String nama = br.readLine();

        System.out.println("\nPilih Jenis Kamar");
        System.out.println("R. Reguler");
        System.out.println("S. Suite");
        System.out.println("P. President");
        System.out.print("Jenis kamar yang dipesan (R/S/P) \t: ");
        String jenis = br.readLine();

        System.out.print("\nLama Menginap \t\t\t: ");
        int lama = Integer.parseInt(br.readLine());

        HotelReservation hotelReservation = new HotelReservation(nama, jenis, lama);

        System.out.println("\n\n---***--- NOTA PEMBAYARAN HOTEL ---***---");
        System.out.println("Nama Pelanggan \t\t\t: " + hotelReservation.getNama());
        System.out.println("Jenis Kamar \t\t\t: " + hotelReservation.getKamar());
        System.out.println("Tarif Penginapan \t\t: Rp " + hotelReservation.getTarif() + ",-");
        System.out.println("====================================================");