Question

7267881在我的文件中作为帐户，如果您执行

，则扫描文件

            System.out.println(Account[2][1]);

它打印回7267881，但是当提示用户是否输入7267881时，它返回它是一个无效的数字...文件中的所有其他帐号都不起作用...请帮我找出原因< / p>

import java.io.File; import java.util.Scanner;

public class AcccountArray {

    public static void main(String[] args) 
    {
        //Scan the file and save account details to array
        File file = new File ("customers.txt");
        System.out.println("Path : " + file.getAbsolutePath());
        try{
            Scanner scanner = new Scanner(new File("customers.txt"));
            String[][] Account = new String[Integer.valueOf(scanner.nextLine())][3];

                    for(int i=0;i<Account.length;i++)
                    {
                        Account[i][0]=scanner.nextLine();
                        Account[i][1]=scanner.nextLine();
                        Account[i][2]=scanner.nextLine();
                    }
                    scanner.close();
                    System.out.println(Account[2][1]);
                Scanner userinput = new Scanner(System.in);
                System.out.println("Please enter account number: ");
                String accountNumber = userinput.next();
                int matchindex = 0;
                Boolean match = false;


                for (int k =0;k<Account.length;k++)
                {
                    if(Account[k][1].equals(accountNumber))
                    {
                        match = true;
                        matchindex = k;
                    }
                }


                if(match)
                {
                    Account ac =  new Account();
                    ac.toString(Account[matchindex][0], Account[matchindex][1], Account[matchindex][2]);
                    System.out.println("Enter 'D' for deposite\nEnter 'W' for withdrawal\nEnter 'Q' for quit");

                    Scanner transaction = new Scanner(System.in);
                    String type = transaction.next();

                    Scanner ammount = new Scanner(System.in);
                    switch (type) {
                    case "D":
                        System.out.println("Enter the ammount : ");
                        float diposit = ammount.nextFloat();
                        float curent = Float.valueOf(Account[matchindex][2]);
                        System.out.println("New balance = "+(curent+diposit));
                        break;
                    case "W":
                        System.out.println("Enter the ammount : ");
                        float withdrawal = ammount.nextFloat();
                        float balance = Float.valueOf(Account[matchindex][2]);
                        System.out.println("New balance = "+(balance-withdrawal));
                        break;
                    case "Q":
                        System.out.println("Exit");
                        break;

                    default:
                        System.out.println("Invalid transaction");

                    }
                }
                else
                {
                    System.out.println("Invalid user account number");
                }


        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

    }

}

文件看起来像

4
John Anderson
4565413
250.00
Louise Carter 
2323472
1250.45 
Paul Johnson
7267881 
942.81
Sarah Wilson  
0982377
311.26

Answer 1

即时错误可以在输入文件中找到。有问题的帐号后面似乎有一个空格。您需要在文件完全中设置帐号，因为它将在探测期间输入，或者在输入时修剪字符串。

但是，您需要学习如何有效地进行调试。我有一些关于如何做到这一点的建议，在Debug Strategy上用Java编写了一个有用的例子。

哪个是不允许帐号＃7267881有效的错误

1 个答案: