Thread: ArrayList question

I am new to programming and new to posting on this forum so please forgive me if I make any mistakes.
I have the following code:

public class BillsDriver 
{
 
 
	public static void main(String[] args) 
	{
		//array of Bills
		ArrayList<Bills> bills = new ArrayList<Bills>();
 
		ArrayList<Income> income1 = new ArrayList<Income>();
 
		boolean money = true;
		while(money)
		{
 
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter income: ");
		double incomes = scan.nextDouble();
 
		Income thisIncome = new Income(incomes);
		income1.add(thisIncome);
 
		System.out.println("More income?(true/false)");
		money = scan.nextBoolean();
		}
 
		printIncome(income1);
 
 
		boolean more = true;
 
		while(more)
		{
			Scanner sc = new Scanner(System.in);
			System.out.println("Enter bill name: ");
			String name = sc.nextLine();
 
			System.out.println("Enter bill amount: ");
			double amount = sc.nextDouble();
 
			Bills thisBill = new Bills(name, amount);
 
			bills.add(thisBill);
 
			System.out.println("More bills?(true/false)");
			more = sc.nextBoolean();
 
		}
 
		printBill(bills);
 
 
	}
 
	public static void printIncome(ArrayList<Income> income) 
	{
		double totals =0;
		for(int i=0; i<income.size(); i++)
		{
			System.out.println("Income total: " + i + income.get(i).toString());
 
			totals += ((Income)income.get(i)).getTotals();
			System.out.println("\tTotal income: \t" + totals);
		}
 
	}
 
	public static void printBill(ArrayList<Bills> bills) 
	{
		//prints out data
		double total = 0;
		for(int i = 0; i < bills.size(); i++)
		{
			//show ArrayList of bills added by user
			System.out.println("Bill number: " + (i+1) + ":" + bills.get(i).toString());
 
 
			//get total amount due
			total += ((Bills) bills.get(i)).getTotal();
			System.out.println("\tTotal amount due: \t" + total);
 
		}
 
	}
 
}

What I have questions about is how to subtract the total of the Bills ArrayList from the total of the Income ArrayList?

Yes.
I have tried adding:
double result = 0;
result = totals - total;
System.out.println("Results: " +result);
But I kept getting different errors to create a totals variable and a total variable.
If possible I just wanted to call the totals and total amounts that are already established and subtract totals - total.

public class BillsDriver 
{
 
 
	public static void main(String[] args) 
	{
		//arrayList of Bills Class
		ArrayList<Bills> bills = new ArrayList<Bills>();
 
		//ArrayList of Income class
		ArrayList<Income> income1 = new ArrayList<Income>();
 
		boolean money = true;
		while(money)
		{
		//get user input for income
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter income: ");
		double incomes = scan.nextDouble();
 
		Income thisIncome = new Income(incomes);
		income1.add(thisIncome);
 
		System.out.println("More income?(true/false)");
		money = scan.nextBoolean();
		}
 
		printIncome(income1);
 
 
		boolean more = true;
 
		while(more)
		{
			//user input for name of bill and amount 
			Scanner sc = new Scanner(System.in);
			System.out.println("Enter bill name: ");
			String name = sc.nextLine();
 
			System.out.println("Enter bill amount: ");
			double amount = sc.nextDouble();
 
			Bills thisBill = new Bills(name, amount);
 
			bills.add(thisBill);
 
			System.out.println("More bills?(true/false)");
			more = sc.nextBoolean();
 
		}
 
		printBill(bills);
 
 
	}
 
	private static void printIncome(ArrayList<Income> income) 
	{
		//prints income data
		double totals =0;
		for(int i=0; i<income.size(); i++)
		{
			//show ArrayList of Income
			System.out.println("Income total: " + i + income.get(i).toString());
 
			//calculates total income
			totals += ((Income)income.get(i)).getTotals();
			System.out.println("\tTotal income: \t" + totals);
		}
 
	}
 
	private static void printBill(ArrayList<Bills> bills) 
	{
		//prints bills data
		double total = 0;
		for(int i = 0; i < bills.size(); i++)
		{
			//show ArrayList of bills added by user
			System.out.println("Bill number: " + (i+1)+ " " + bills.get(i).toString());
 
 
			//get total amount due
			total += ((Bills) bills.get(i)).getTotal();
			System.out.println("\tTotal amount due: \t" + total);
 
		}
 
	}
	 public static void grandTotal()
	 {
 
		double grandTotal = 0;
		grandTotal = totals - total;
	 System.out.println("Results: " + grandTotal);
	 }
 
 
 
}

The errors are on totals and total within grandTotal:
Multiple markers at this line
- totals cannot be resolved
- total cannot be resolved

No they are defined in different methods.
totals is defined in private static void printIncome(ArrayList<Income> income)
and
total is defined in private static void printBills(ArrayList<Bills> bills)