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Discover how to build a simple calculator in Java using just one method for all operations, making your code cleaner and more efficient.
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Building a Simple Calculator with One Method in Java

Creating a calculator application can often lead to a lot of repetitive code, especially if you're using multiple methods for addition, subtraction, multiplication, and division. If you're looking for a way to simplify your code structure in Java, this guide will guide you through creating a calculator that operates using just one method for all arithmetic operations.

The Problem Statement

You’re likely familiar with the challenge of writing separate methods for each mathematical operation:

Addition: add(a, b)

Subtraction: subtract(a, b)

Multiplication: multiply(a, b)

Division: divide(a, b)

This can make your program bulky and harder to maintain. What if there was a way to condense this into a single method? That's exactly what we aim to do in this guide.

Solution Overview

To achieve this, we can use Java Enums combined with lambda expressions. This strategy allows us to define a set of operations in a structured manner while leveraging a single calculation method.

Step-by-Step Implementation

Set Up Your Java Project: Start by creating a new Java class, for example, Main.java.

Import Necessary Packages: You will need the java.util.Scanner and java.util.function.BiFunction packages.

Define Your Main Class: In your Main class, initiate the scanner for user input.

Create an Enum for Operations: Define an enum OperationType that encapsulates each arithmetic operation and its corresponding lambda expression.

Implement the Calculation Method: This method will take an operation and apply it to the two user-defined numbers.

Here is how the code would look:

[[See Video to Reveal this Text or Code Snippet]]

Key Components of the Code:

Enum Definition: The OperationType enum defines four operations with their symbols and corresponding lambda functions.

User Input Handling: The program prompts the user to choose an operation and input two numbers.

Validation: It uses fromSign to ensure that only valid operations proceed.

Single Calculation Method: The calculation method takes an OperationType and applies it to the numbers, returning the result.

Conclusion

By linking operations to their corresponding lambda functions and wrapping them in an enum, we've efficiently consolidated our calculator's functionality into a single method. This approach not only keeps your code clean but also extends easily if you'd like to add more operations in the future.

Embrace this design pattern for a neat, maintainable Java calculator implementation without the clutter of multiple methods! Happy coding!