[galva]

Hello

I wonder if someone can help me with a simple ATM machine
that can deposit, withdrawl an show the 10 latest transactions in an array of 10 index values.
The problem is that i can't see the transactions after the 10:th.
the program don't take the amount or don't display the transactions after the 10:th operation.

Could someone help me with this.
I have written a code and i don't know wath wrong i doo in the soure code.

Here is the source code:

import java.util.Scanner;


public class BankoMat 
{
	
    public static void main(String[] args)
    {
         Scanner keyboard = new Scanner(System.in);
         
         int amount = 0;
         int choice = 0;
         int [] transactions = new int[10];
         int sum;
         int balance = 0;
         
         while (choice != 4)
         {
         	choice = menu();
         	switch(choice)
         	{
         		case 1:
         			System.out.print("Enter amount to deposit? :");
         			sum = keyboard.nextInt();
         				if(sum == 0)
         				{
         				System.out.print("Wrong amount.");
         				System.out.println();
         				System.out.println();
         				}
         				else
         				{
         				amount = (int) + sum;
         				makeTransactions(amount, transactions);
         				}
         				   break;
         		
         		case 2:
         				System.out.print("Hoe much do you want to withdrawl?: ");
         				sum = keyboard.nextInt();
         					if(sum == 0)
         					{
         						System.out.print("Wrong amount.");
         						System.out.println();
         						System.out.println();
         					}
         						else
         						{
         							amount = (int) - sum;
         							makeTransactions(amount, transactions);
         						}
         						break;
         		
         		case 3:
         				showTransactions(transactions, balance);
         				break;
         				
         		case 4:
         				System.out.println("You chosed to end ");
         				break;
         	}	
         	
         }
    }
    
    
    	public static int menu()
    	{
    		Scanner keyboard = new Scanner(System.in);
    		int choice = 0;
    		
    		System.out.println("Simple ATM");
    		System.out.println();
    		System.out.println("1. Deposit ");
    		System.out.println("2. Withdrawl ");
    		System.out.println("3. transactions ");
    		System.out.println("4. End ");
    		System.out.println();
    		System.out.println("Your choice ");
    		
    		choice = keyboard.nextInt();
    		return choice;
    	}
    	
		public static void showTransactions(int [] transactions, int balance)
		{
			System.out.println();
			System.out.println("Last transactions");
			System.out.println();
			
				for(int i = 0; i < transactions.length-1; i++)
				{
					if(transactions[i] == 0)
					{
						System.out.print("");
					}
					
						else
						{
							System.out.print(transactions[i] + "\n");
							balance = balance + transactions[i];
						
						}
			
				}
			System.out.println();
			System.out.println("Balance: " + balance + " kr" + "\n" );
			System.out.println();		

		}
		
		public static void makeTransactions(int amount, int [] transactions)
		{
			int position = findNr(transactions);
			if(position == -1)
			{
				moveTrans(transactions);
					position = findNr(transactions);
					transactions[position] = amount;
			}
			else
			{
				transactions[position] = amount;
			}	
				
		}
		
		public static int findNr(int [] transactions)
		{
			int position = -1;
			
			for(int i = 0; i < transactions.length-1; i++)
			{
				if(transactions[i] == 0)
				{
					position = i;
					break;
				}	
			}
			return position;
		}
		
		public static void moveTrans(int [] transactions)
		{
			for(int i = 0; i < transactions.length-1; i++)
				
				transactions[0] = transactions[i + 1] ;
				
		}
		

}

This post has been edited by baavgai: 07 December 2010 - 01:54 PM
Reason for edit:: tagged

[DaneAU]

This might clear things up a little for you. Have a read and see how you go

[pbl]

All your for() loop but the one in moveTrans should be

for(int i = 0; i < transactions.length; i++)

not

for(int i = 0; i < transactions.length-1; i++)

[macosxnerd101]

Use the modulus operator. Take transactionIndex%10, and that's your index for the transaction. Also, remember that arrays are indexed from 0 through length-1.

[galva]

macosxnerd101, on 08 December 2010 - 09:40 AM, said:

Use the modulus operator. Take transactionIndex%10, and that's your index for the transaction. Also, remember that arrays are indexed from 0 through length-1.

hello again.

I tryed to change the method moveTrans()
I wrote the this instead:

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

transactions[transactions.length-1] = 0;

}

The problem of the arrays are fixed.
I found a new problem and it is when i do withdrawl and after withdrawl when i look the balance, there something wrong
in the calculation, it seems that the balance is wrong, for example. What wrong is with my code? It does't seem to be correct balance:
Can someone help me of this problem?


10 last transactions:

1
-10
10
10
10
10
10
9
-55

Balance: -5 kr

[galva]

it seems strange. I think the array only save the 10 transactions. But what about the balance?
I Try to make about 15 transactions with deposit and withdrawl. Look att the balance. It seems strange to me????
Can you note something wrong that I don't understand, maybe is the array of only 10 saved index?
Anyway the balance should save all the transactions from the beginning...
Do you have any idea about that, so the balance will save all transactions from beginning?


this is what the program should do:
array of 10 index were the latest 10 transactions will be saved.
The balance should save all the deposit and withdrawl from the beginning.
the program should show the 10 latest transaction and show the final balance from all inputs of the user.

Can someone help me out how i can go thru this problem.