import java.util.*;
public class Calculator 
{
	public static void main(String[] args)
	{
		double[] numbers = new double[2];
		
		displayMenu(numbers);
	}
	// Method to show menu
	private static void displayMenu(double[] numbersIn)
	{
		Scanner sc = new Scanner(System.in);
		char choice = 0;
		
		do
		{	
			System.out.println("\t\t\tCustom Calculator Version 0.2");
			System.out.println("[1] Add");
			System.out.println("[2] Divide");
			System.out.println("[3] Multiple");
			System.out.println("[4] Subtract");
			System.out.println("[5] Exit");
			System.out.println();
			System.out.print("Please enter your choice: ");
			choice = sc.next().charAt(0);
			
			switch(choice)
			{
				case '1':	inputNumbers(numbersIn);
							totalNumbers(numbersIn, choice);
							break;
				case '2':	inputNumbers(numbersIn);
							totalNumbers(numbersIn, choice);
							break;
				case '3':	inputNumbers(numbersIn);
							totalNumbers(numbersIn, choice);
							break;
				case '4':	inputNumbers(numbersIn);
							totalNumbers(numbersIn, choice);
							break;		
							
				default: System.out.println("Please select between 1-5");			
			}
		} while (choice != 5);
		System.out.println("Goodbye");
		
	}
	
	// Method to get the numbers
	private static void inputNumbers(double[] numbersIn)
	{
		Scanner sc = new Scanner(System.in);
		for (int i = 0; i < numbersIn.length; i++)
		{
			System.out.print("Please enter number: " + (i+1) + " - ");
			numbersIn[i] = sc.nextDouble();
		}		
	}
	
	// Method to get the total
	private static void totalNumbers(double[] numbersIn, char choiceIn)
	{
		double total = 0;
		if (choiceIn == '1')
		{
			for (int i = 0; i < numbersIn.length; i++)
			{
				total = numbersIn[i] + numbersIn[i];
			}
		}
		else if (choiceIn == '2')
		{
			for (int i = 0; i < numbersIn.length; i++)
			{
				total = numbersIn[i] / numbersIn[i];
			}
		}
		else if (choiceIn == '3')
		{
			for (int i = 0; i < numbersIn.length; i++)
			{
				total = numbersIn[i] * numbersIn[i];
			}
		}
		else if (choiceIn == '4')
		{
			for (int i = 0; i < numbersIn.length; i++)
			{
				total = numbersIn[i] - numbersIn[i];
			}
		}
		System.out.println();
		System.out.println("Total is: " + total);
		System.out.println();
	}
}