Assignment2.java

import java.util.InputMismatchException;
import java.util.Scanner;

class Calculator {

    public int add(int a, int b) {
        return a + b;
    }

    public double add(double a, double b) {
        return a + b;
    }

    public int add(int a, int b, int c) {
        return a + b + c;
    }

    public int subtract(int a, int b) {
        return a - b;
    }

    public double multiply(double a, double b) {
        return a * b;
    }

    public int divide(int a, int b) throws ArithmeticException {
        if (b == 0) {
            throw new ArithmeticException("Error: Division by zero is not allowed.");
        }
        return a / b;
    }
}

public class Main {
    private Calculator calculator;
    private Scanner scanner;

    public Main() {
        calculator = new Calculator();
        scanner = new Scanner(System.in);
    }

    private void handleInputMismatch() {
        System.out.println("Error: Invalid input. Please enter the correct data type.");
        scanner.nextLine(); 
    }
    
    public void performAddition() {
        System.out.println("\n--- Addition Options ---");
        System.out.println("1. Add two integers (int, int)");
        System.out.println("2. Add two doubles (double, double)");
        System.out.println("3. Add three integers (int, int, int)");
        System.out.print("Enter choice: ");

        try {
            int choice = scanner.nextInt();
            scanner.nextLine(); 

            switch (choice) {
                case 1:
                    System.out.print("Enter first integer: ");
                    int i1 = scanner.nextInt();
                    System.out.print("Enter second integer: ");
                    int i2 = scanner.nextInt();
                    System.out.println("Result: " + calculator.add(i1, i2));
                    break;
                case 2:
                    System.out.print("Enter first double: ");
                    double d1 = scanner.nextDouble();
                    System.out.print("Enter second double: ");
                    double d2 = scanner.nextDouble();
                    System.out.println("Result: " + calculator.add(d1, d2));
                    break;
                case 3:
                    System.out.print("Enter first integer: ");
                    int i3 = scanner.nextInt();
                    System.out.print("Enter second integer: ");
                    int i4 = scanner.nextInt();
                    System.out.print("Enter third integer: ");
                    int i5 = scanner.nextInt();
                    System.out.println("Result: " + calculator.add(i3, i4, i5));
                    break;
                default:
                    System.out.println("Invalid addition choice.");
            }
        } catch (InputMismatchException e) {
            handleInputMismatch();
        } finally {
            scanner.nextLine();
        }
    }

    public void performSubtraction() {
        try {
            System.out.print("Enter first integer: ");
            int a = scanner.nextInt();
            System.out.print("Enter second integer: ");
            int b = scanner.nextInt();
            System.out.println("Result: " + calculator.subtract(a, b));
        } catch (InputMismatchException e) {
            handleInputMismatch();
        } finally {
            scanner.nextLine();
        }
    }

    public void performMultiplication() {
        try {
            System.out.print("Enter first double: ");
            double a = scanner.nextDouble();
            System.out.print("Enter second double: ");
            double b = scanner.nextDouble();
            System.out.println("Result: " + calculator.multiply(a, b));
        } catch (InputMismatchException e) {
            handleInputMismatch();
        } finally {
            scanner.nextLine();
        }
    }

    public void performDivision() {
        try {
            System.out.print("Enter dividend (integer): ");
            int a = scanner.nextInt();
            System.out.print("Enter divisor (integer): ");
            int b = scanner.nextInt();
            
            int result = calculator.divide(a, b);
            System.out.println("Result: " + result);

        } catch (InputMismatchException e) {
            handleInputMismatch();
        } catch (ArithmeticException e) {
            System.out.println(e.getMessage());
        } finally {
            scanner.nextLine(); 
        }
    }

    public void mainMenu() {
        int choice = 0;
        do {
            System.out.println("\nWelcome to the Calculator Application!");
            System.out.println("1. Add Numbers (Overloaded)");
            System.out.println("2. Subtract Numbers");
            System.out.println("3. Multiply Numbers");
            System.out.println("4. Divide Numbers (Exception Handled)");
            System.out.println("5. Exit");
            System.out.print("Enter your choice: ");

            try {
                choice = scanner.nextInt();
                scanner.nextLine(); 

                switch (choice) {
                    case 1: performAddition(); break;
                    case 2: performSubtraction(); break;
                    case 3: performMultiplication(); break;
                    case 4: performDivision(); break;
                    case 5:
                        System.out.println("Exiting application.");
                        break;
                    default:
                        System.out.println("Invalid choice. Please enter a number from 1 to 5.");
                }
            } catch (InputMismatchException e) {
                System.out.println("Error: Invalid input. Please enter a number (1-5).");
                choice = 0; 
                scanner.nextLine(); 
            }
        } while (choice != 5);
    }

    public static void main(String[] args) {
        Main app = new Main();
        try {
            app.mainMenu();
        } finally {
            if (app.scanner != null) {
                app.scanner.close();
            }
        }
    }
}