Calculator

/**
 * Created by Nenad on 3/31/2016.
 */

import java.util.Scanner;

public class Calculator {

    public static void main(String[] args) {


        Scanner reader = new Scanner(System.in);

        System.out.println("Basic Calculator");
        System.out.println("----------------");
        System.out.println(" ");
        System.out.println("Type in 2 integer numbers: ");
        System.out.println("-------------------------");
        System.out.println(" ");
        System.out.println("First integer number: ");

        while (!reader.hasNextInt()){
            reader.next();
            System.out.println("The first number was not an integer, please try again: ");
        }
        int a = reader.nextInt();
        System.out.println("Second integer number: ");

        while (!reader.hasNextInt()){
            reader.next();
            System.out.println("The second number was not an integer, please try again: ");
        }
        int b = reader.nextInt();

        System.out.println("Type in 2 Double numbers: ");
        System.out.println("--------------------------");
        System.out.println("First double number: ");

        while (!reader.hasNextDouble()){
            reader.next();
            System.out.println("The first number was not a double, please try again: ");
        }
        double c = reader.nextDouble();
        System.out.println("Second double number: ");

        while (!reader.hasNextDouble()){
            reader.next();
            System.out.println("The second number was not a double, please try again: ");
        }
        double d = reader.nextDouble();

        System.out.println(" ");
        System.out.println("Integer number calculator");
        System.out.println("-----------------------");
        System.out.println("Addition result: " + plus(a, b));
        System.out.println("Subtraction result: " + minus(a, b));
        System.out.println("Multiplication result: " + mult(a, b));
        System.out.println("Division result: " + div(a, b));
        System.out.println("Rest: " + rest(a, b));
        System.out.println(" ");
        System.out.println(" ");
        System.out.println("Double number calculator");
        System.out.println("-----------------------");
        System.out.println("Addition result: " + plus(c, d));
        System.out.println("Subtraction result: " + minus(c, d));
        System.out.println("Multiplication result: " + mult(c, d));
        System.out.println("Division result: " + div(c, d));
        System.out.println("Rest: " + rest(c, d));

    }

    private static int plus (int x, int y){
        return (x + y);
    }
    private static int minus (int x, int y){
        return (x - y);
    }
    private static int mult (int x, int y){
        return (x * y);
    }
    private static int div (int x, int y){
        return (x / y);
    }
    private static int rest (int x, int y){
        return (x % y);
    }



    private static double plus (double x, double y){
        return (x + y);
    }
    private static double minus (double x ,double y){
        return (x - y);
    }
    private static double mult (double x, double y){
        return (x * y);
    }
    private static double div (double x, double y){
        return (x / y);
    }
    private static double rest (double x, double y){
        return (x % y);
    }

}