java - 为什么我的位置是0？什么时候应该是1

Question

我学的是Java，现在在ArrayList，我写了一些关于银行的方法，当我想在特定分行添加新客户时，位置总是返回0。这是我的方法的源代码正在谈论:

• 主类中的实例:

  public static Scanner scanner = new Scanner(System.in);
  public static Bank newBank = new Bank("BMCE");
  

• 主类(添加新客户的静态方法):

  public static void addNewCostumer(){
  System.out.println("Choose a branch :");
  String branchChoosed = scanner.nextLine();
  Branches branches = newBank.queryBranch(branchChoosed);
  if(branches == null){
      System.out.println("There are a problem, or you are entered a wrong name of branch");
  
  }
  else{
      System.out.println("Enter the name costumer :");
      String nameOfCostumer = scanner.nextLine();
      System.out.println("Enter the transaction number :");
      double transactions = scanner.nextDouble();
      scanner.nextLine();
      if(newBank.addNewCostumer(branches,nameOfCostumer,transactions)){
          System.out.println("The costumer was created in branch name :"+branches.getNameOfBranch());
  
  
      }else{
  
          System.out.println("Sorry you dindn't create a costumer in "+branches.getNameOfBranch()+" Try again please :)");
  
      }
  
  }
  

• Bank 类中的实例:

  private String name;
  private ArrayList<Branches> branchesArrayList = new ArrayList<>();
  

• 银行类别:

  public boolean addNewCostumer(Branches nameOfExistingBranch,String nameOfNewCostumer,double newTransaction){
  int position = findBranch(nameOfExistingBranch);
  
  
  if(position<0){
      System.out.println("There is not branch with this name");
      return false;
  }
  else{
      if(this.branchesArrayList.get(position).findCostumer(nameOfNewCostumer)>=0){
          System.out.println("You have already an existing costumer with that name");
          return false;
      }
      else{
  
          this.branchesArrayList.get(position).addNewCostumer(nameOfNewCostumer,newTransaction);
          return true;
  
      }
  
  }
  
  }
  

• 查找分支的方法:

  public int findBranch(Branches branches){
  int position = this.branchesArrayList.indexOf(branches);
  if(position>=0){
  
      return position;
  
  }
  else
      return -1;
  }
  

• 输入:

  0-Mdiq
  1-卡萨
  2-拉巴特

当我向 Rabat 或 Casa Branch 添加新客户时，该客户始终记录在 Mdiq(位置 0)中。

Answer 1

我发现代码中存在错误，因此问题已解决。在查询方法中，我编写了 this.branchesArrayList.get(0); 而不是使用位置作为参数。