import java.util.Scanner;

public class Calculator
{
    public static void main(String[] args)
    {   
        double num1, num2, answer;
        int response = 1;
        String op;
        Scanner in = new Scanner(System.in);
        System.out.println("This program will do addition and subtraction calcualtions ");     
        while(response == 1)
        {  System.out.println("Please enter a number, an operator (+ or -), and another number. ");
           num1 = in.nextDouble();
           op = in.next();
           num2 = in.nextDouble(); 
           
           if(op.equals("+"))
                answer = add(num1, num2);  // these methods are here just to show how to call method and how to write them
           else 
                answer = sub(num1,num2);
           System.out.println("The answer is " + answer);  
           System.out.println("If you want to continue, enter 1, otherwise enter 2");
           response = in.nextInt();
        }
    }// end main
    
    public static double add(double number1, double number2)
    {   return number1 + number2;
    }// end add method
    
    public static double sub(double numb1, double numb2)
    {
            System.out.println("Not impelemnted yet");  // example of stubbing in a method
            return 0.0;
    }
}  // class Calculator