Java Calculator Application

---

Overview

The Java Calculator Application is a console-based program written in Java, designed to demonstrate key object-oriented programming (OOP) concepts, including:

• Method Overloading
• Encapsulation
• Modular Programming

This application allows users to perform basic arithmetic operations (addition, subtraction, multiplication, division) with both integer and floating-point numbers.

It is user-friendly, error-tolerant, and educational for beginners learning Java and OOP.

---

Features

• Addition
  • Add two numbers (integer or double) or three integers
  • Demonstrates method overloading
• Subtraction
  • Subtract two integers
• Multiplication
  • Multiply two numbers (integer or double)
• Division
  • Divide two integers
  • Handles division by zero gracefully
• Menu-driven Interface
  • Easy navigation for multiple calculations
• Error Handling
  • Validates user input and prevents runtime errors

---

Technologies Used

• Java
• OOP Concepts: Classes, objects, method overloading, encapsulation
• Scanner Class for user input
• Control statements: switch-case and do-while loops

---

Code Structure

CalculatorApp.java ├─ Calculator # Performs arithmetic operations │ ├─ add() # Overloaded: 2 ints, 2 doubles, 3 ints │ ├─ subtract() # Subtracts 2 integers │ ├─ multiply() # Multiplies 2 doubles │ └─ divide() # Divides 2 integers with zero-check │ ├─ UserInterface # Handles user interaction │ ├─ performAddition() │ ├─ performSubtraction() │ ├─ performMultiplication() │ ├─ performDivision() │ └─ mainMenu() # Menu navigation │ └─ CalculatorApp # Main class to run the program

SAMPLE CONSOLE OUTPUT

--- Calculator Application ---

1. Add Numbers
2. Subtract Numbers
3. Multiply Numbers
4. Divide Numbers
5. Exit Enter your choice: 1 Do you want to add 2 or 3 numbers? 2 Enter first number: 5 Enter second number: 3 Result: 8

Enter your choice: 4 Enter numerator: 10 Enter denominator: 0 Error: Cannot divide by zero. Result: 0