簡單的ATM。在ATM程序中取代零交易而不是ATM交易

Question

我已經制作了自動提款機（ATM）程序，但我無法弄清楚什麼是錯的。除了交易是零線之外，一切都在起作用。我一定弄錯了一些東西..我認爲這是「showTransactions」方法的一些東西。感謝幫助！

import java.util.Scanner; 

public class ATM { 
     private static int position = - 1; 
    public static void main(String[] args) { 
     Scanner input = new Scanner(System.in); 
     // Set a value to the various 
     int amount = 0; 
     int choice = 0; 
     int sum; 
     int balance = 0; 
     int[] trans = new int[10]; 

     while (choice != 4) { 
      choice = menu(); 
      switch (choice) { 

      case 1: 
       System.out.print("How much would you like to deposit?: "); 
       System.out.println(); 

       sum = input.nextInt(); 

       if (sum == 0) { 
        System.out.print("Unable to deposit"); 
        System.out.println(); 
        System.out.println(); 
       } else { 
        balance += sum; 
        makeTransactions(trans, amount); 
       } 
       break; 

      case 2: 
       System.out.print("How much would you like to withdraw?"); 
       System.out.println(); 

       sum = input.nextInt(); 

       if (sum == 0 || sum > balance) { 
        System.out.print("Unable to withdraw"); 
        System.out.println(); 
        System.out.println(); 
       } else { 
        balance += - sum; 
        makeTransactions(trans, amount); 
       } 
       break; 

      case 3: 
       showTransactions(trans, balance); 
       break; 

      case 4: 
       System.out.println("You chosed to end "); 
       break; 
      } 

     } 
    } 

    public static int menu() { 
     Scanner input = new Scanner(System.in); 
     int choice = 0; 

     System.out.println("Cash machine"); 
     System.out.println(); 
     System.out.println("------------------------"); 
     System.out.println("1 - Deposit   *"); 
     System.out.println("2 - Withdraw   *"); 
     System.out.println("3 - View transactions *"); 
     System.out.println("4 - End cash machine *"); 
     System.out.println("------------------------"); 
     System.out.println(); 
     System.out.println("Enter your choice: "); 

     choice = input.nextInt(); 
     return choice; 
    } 

    public static void showTransactions(int[] trans, int balance) { 
     System.out.println(); 
     System.out.println("Previous 10 transactions"); 
     System.out.println(); 

     for (int i = 0; i < trans.length; i++) { 
      if(trans[i] != 0) 
      { 
       System.out.print(trans[i] + "\n"); 
      } 

       else 
       { 
        System.out.print(trans[i] + "\n"); 
        balance = balance + trans[i]; 

       } 

     } 
     System.out.println(); 
     System.out.println("Balance: " + balance + " kr" + "\n"); 
     System.out.println(); 

    } 

    public static void makeTransactions(int[] trans, int amount) { 
     int position = findNr(trans); 
     if(position == -1) 
     { 
      moveTrans(trans); 
       position = findNr(trans); 
       trans[position] = amount; 
     } 
     else { 
      trans[position] = amount; 
     } 

    } 

    public static int findNr(int[] trans) { 
     int position = -1; 

     for (int i = 0; i < trans.length - 1; i++) { 
      if (trans[i] == 0) { 
       position = i; 
       break; 
      } 
     } 
     return position; 
    } 

    public static void moveTrans(int[] trans) { 
     for (int i = 0; i < trans.length; i++) 
      trans[i - 1] = trans[i]; 

    } 

} 

Answer 1

case 1: 
      System.out.print("How much would you like to deposit?: "); 
      System.out.println(); 

      sum = input.nextInt(); 

      if (sum == 0) { 
       System.out.print("Unable to deposit"); 
       System.out.println(); 
       System.out.println(); 
      } else { 
       balance += sum; 
       makeTransactions(trans, amount); 
      } 
      break; 

在上面的代碼，當你調用makeTransactions方法你逝去amount作爲參數，你永遠不會改變，即它始終是0。我想你應該在sum傳遞，因爲這是在那裏你正在存儲用戶輸入的值。

Answer 2

你的邏輯是說IF trans [i] EQUALS 0 then print why？也許改變

if(trans[i] == 0) 

到

if(trans[i] != 0) 

或者爲什麼不全部打印出來，他們是交易的一部分反正。