Building a Calculator Laravel Application from Scratch: A Step-by-Step Guide

Creating web applications using Laravel can be both an enjoyable and educational experience, especially when building something as practical as a calculator. Laravel, known for its elegant syntax and robust features, provides the perfect platform for developing scalable web apps from the ground up.

In this step-by-step guide, we’ll walk you through the process of building a basic calculator Laravel application from scratch. Whether you’re just getting started with Laravel or brushing up your skills, this tutorial will provide the foundational knowledge you need.

Why Build a Calculator App in Laravel?

Before diving into the code, it’s worth understanding why a calculator app is a great beginner-level project for Laravel developers:

Covers Core Laravel Concepts: Routing, controllers, views, and form handling.

Simple Business Logic: Arithmetic operations are easy to implement and test.

Frontend and Backend Integration: You'll learn to manage data between the front and back ends efficiently.

Reusable Code Structure: Even a simple calculator sets the stage for larger Laravel applications.

Step 1: Setting Up a New Laravel Project

First, make sure you have Composer and Laravel installed. Then, create a new Laravel project by running the following command:

Navigate to your project directory:

Set the correct permissions and start the development server:

Visit http://localhost:8000 to verify the Laravel welcome screen appears.

Step 2: Create Routes for the Calculator

Open the routes/web.php file. This file will define the routes for your calculator.

These two routes will handle displaying the calculator form and processing the calculation results.

Step 3: Create the Calculator Controller

Generate a controller using Artisan:

Open app/Http/Controllers/CalculatorController.php and update it with the following code:

php

namespace AppHttpControllers; use IlluminateHttpRequest; class CalculatorController extends Controller { public function index() { return view('calculator'); } public function calculate(Request $request) { $request->validate([ 'number1' => 'required|numeric', 'number2' => 'required|numeric', 'operation' => 'required' ]); $num1 = $request->input('number1'); $num2 = $request->input('number2'); $operation = $request->input('operation'); $result = 0; switch ($operation) { case 'add': $result = $num1 + $num2; break; case 'subtract': $result = $num1 - $num2; break; case 'multiply': $result = $num1 * $num2; break; case 'divide': $result = $num2 != 0 ? $num1 / $num2 : 'Error: Division by zero'; break; default: $result = 'Invalid operation'; } return view('calculator', compact('result')); } }

Step 4: Build the Calculator View

Create a new file named calculator.blade.php in the resources/views directory.

html

<!DOCTYPE html> <html> <head> <title>Laravel Calculator</title> <style> body { font-family: Arial, sans-serif; padding: 20px; } .calculator { max-width: 400px; margin: auto; } input, select, button { width: 100%; padding: 10px; margin: 5px 0; } </style> </head> <body> <div class="calculator"> <h2>Laravel Calculator</h2> @if(isset($result)) <h3>Result: {{ $result }}</h3> @endif <form method="POST" action="/calculate"> @csrf <input type="number" name="number1" placeholder="Enter first number" required> <input type="number" name="number2" placeholder="Enter second number" required> <select name="operation" required> <option value="add">Add</option> <option value="subtract">Subtract</option> <option value="multiply">Multiply</option> <option value="divide">Divide</option> </select> <button type="submit">Calculate</button> </form> @if ($errors->any()) <div> <ul style="color: red;"> @foreach ($errors->all() as $error) <li>{{ $error }}</li> @endforeach </ul> </div> @endif </div> </body> </html>

This view provides a user-friendly interface for inputting values and selecting operations. It also displays any validation errors and the final result.

Step 5: Testing the Application

Start your Laravel server if it’s not already running:

Then navigate to http://localhost:8000/calculator in your browser. You should see the calculator UI. Try performing operations like addition, subtraction, multiplication, and division.

Step 6: Polish and Extend (Optional)

You can enhance the calculator further with the following:

AJAX Integration: Make the form submission dynamic using JavaScript and AJAX.

Input History: Store and display calculation history using Laravel sessions.

Advanced Functions: Add support for square roots, powers, or even trigonometric functions.

Validation Feedback: Show real-time validation messages using Laravel's built-in validation rules and custom messages.

Final Thoughts

Developing a calculator application from scratch in Laravel not only strengthens your fundamental understanding of MVC (Model-View-Controller) architecture but also builds your confidence in using Laravel’s elegant toolset. It's a great way to learn how routing, controllers, request handling, and blade templates work together seamlessly in a Laravel environment.

If you’re looking to go beyond basic projects or require professional support in turning your Laravel ideas into scalable solutions, consider working with experts who specialize in Laravel Application Development Services to accelerate your goals.