Question

我的程序运行，但这是一个逻辑错误，我无法找到它。我输入了名称和所有内容，但我认为他们没有保存，因为当我选择打印行程时，它只保留输出电话号码，并且名称打印为空

import java.util.*;
class Trip{

   private static String customerName;
   private static String mobileNo;
   private static String reservationCode;
   public static int totalReservations=0;
   public static Scanner input=new Scanner (System.in);



   public Trip(){//The constructer
      customerName = " ";
      mobileNo = " "; 

    }

   public Trip(String Name, String MobileNo) {
                   customerName=Name;
                   mobileNo=MobileNo;

             totalReservations++; //increase the total reservations
   }

   public void setcustomerName(String Name){

       customerName = Name;
   }

   public void setmobileNo(String MobileNo){

       mobileNo = MobileNo;
   }


//Getters

   public String getcustomerName() {  
      return customerName;
   }

   public String getmobileNo() {   
      return mobileNo;
   }

     public String getreservationCode() {
      return reservationCode;
   }


   public static void generateReservationCode(){   

   }

   public static void printTripInfo(){   
   System.out.println("Customer Name:"+customerName);   
   System.out.println("Phone Number:"+mobileNo); 



  }
}//end class trip


   public class CabCompany{
   private static int reservations_size=20;
   private static Trip[] trip;
   Trip newTrip;
   public int totalNumber=0;   
   public static int user;
   public static Scanner input=new Scanner (System.in);

   public static void main(String[]args){//MAIN
      trip=new Trip[reservations_size];

      do{

         System.out.println("1. Add a new trip\n2. Find a trip by reservation code\n3. List all trips\n");
         user=input.nextInt();

         if ( user == 1) {

            System.out.println("Name:");
            String Name = input.nextLine();
            input.nextLine();

            System.out.println("MobileNo:");
            String MobileNo = input.next();



            CabCompany Y = new CabCompany();
            boolean flag;
            flag = Y.addTrip(Name,MobileNo);
            if( flag == true) {
               System.out.println("the trip has been added succssfully");

            } else if (flag == false){
               System.out.println("hasn't been added");
             }
         }   

         if( user == 2) {
            printAll();

         }

         if( user == 3 ){
         System.out.println("The total Reservations is:"+Trip.totalReservations);
         }

         } while (user != 7);//BREAK 
      }


    public boolean addTrip(String customerName,String mobileNo){

          boolean flag = true;

         if ((mobileNo.length() == 10)) {       
         newTrip=new Trip(customerName, mobileNo);
         int i = Trip.totalReservations - 1;
         newTrip.generateReservationCode();
         trip[i] = newTrip;

            flag = true;  




} else {
          flag = false;

      }

      return flag;
   }      


   public static void printAll() {

      for(int t=0; t<Trip.totalReservations; t++){
          trip[t].printTripInfo();      

      }
   }

}

Answer 1

好的，这里有好几件事。要回答你的问题，我想你是在谈论方法

public static void printTripInfo(){
  Trip rr=new Trip();
  CabCompany K=new CabCompany();
  for(int y=0;y<2;y++)
  System.out.println("Customer Name:"+rr.getcustomerName());   
  System.out.println("Phone Number:"+rr.getmobileNo());   
}

在这里，在第一行，您创建一个新的空行程（rr），您打印。这个方法应该是：

 public static void printTripInfo(){
      System.out.println("Customer Name:"+getcustomerName());   
      System.out.println("Phone Number:"+getmobileNo());   
    }

此外，还有一个可用于此的内置方法，称为toString（）。其他注意事项：变量名称不应该以大写字母开头，并且应该具有含义（TYY，Y，...，不是好名字），并且可以删除和替换您的第一个构造函数，如下所示：

class  Trip{
private String customerName="";
private String mobileNo="";
private String day="";
private String date="";
private String time="";
...
...

但是，您的代码中还有一些其他问题，我建议您阅读更多关于java dev或者关注教程的内容;）

Answer 2

在printTripInfo（）方法中，您正在创建一个新的Trip对象将永远是空的： -

 public static void printTripInfo(){
//Creating a new Trip object, which is empty       
Trip rr=new Trip();

 //Printing the values from above object, which will be blank
   System.out.println("Customer Name:"+rr.getcustomerName());   
   System.out.println("Phone Number:"+rr.getmobileNo());   

}

程序什么都不打印（对象和类）

2 个答案: