🧪 Composer Practice Exercises (PHP)

🟢 Level 1: Basics (Beginner)

✅ Exercise 1: Install Composer

• Install Composer on your system
• Run:

composer -v

👉 Output should show version

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✅ Exercise 2: Create First Project

• Create a new folder composer-practice
• Run:

composer init

• Fill details (name, description, etc.)

👉 Check: composer.json created

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✅ Exercise 3: Install First Package

Install a simple package:

composer require monolog/monolog

👉 Task:

• Open composer.json
• Verify package added
• Check vendor/ folder

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🟡 Level 2: Usage (Intermediate)

✅ Exercise 4: Use Installed Package

👉 Create index.php

<?php
require 'vendor/autoload.php';use Monolog\Logger;
use Monolog\Handler\StreamHandler;$log = new Logger('app');
$log->pushHandler(new StreamHandler('app.log', Logger::WARNING));$log->warning('This is a warning!');
$log->error('This is an error!');

👉 Task:

• Run file
• Check app.log created

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✅ Exercise 5: Install PHPMailer

composer require phpmailer/phpmailer

👉 Task:

• Create a PHP script to send email
• (Use dummy SMTP if needed)

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✅ Exercise 6: Remove Package

composer remove monolog/monolog

👉 Task:

• Check:
  • composer.json
  • vendor/

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🟠 Level 3: Autoloading

✅ Exercise 7: Manual vs Autoload

👉 Without Composer:

• Create 3 PHP class files
• Include using require

👉 With Composer:

• Use:

require 'vendor/autoload.php';

👉 Task:

• Compare code length and readability

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✅ Exercise 8: PSR-4 Autoload

👉 Step 1: Update composer.json

{
  "autoload": {
    "psr-4": {
      "App\\": "src/"
    }
  }
}

👉 Step 2:

composer dump-autoload

👉 Step 3: Create class

📁 src/User.php

<?php
namespace App;class User {
    public function sayHello() {
        return "Hello User!";
    }
}

👉 Step 4: Use it

<?php
require 'vendor/autoload.php';use App\User;$user = new User();
echo $user->sayHello();

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🔴 Level 4: Real-World Practice

✅ Exercise 9: Build Logger System

👉 Task:

• Use Monolog
• Create logs for:
  • Login success
  • Login failure
  • Errors

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✅ Exercise 10: API Integration

👉 Task:

• Install:

composer require guzzlehttp/guzzle

• Fetch data from:

https://jsonplaceholder.typicode.com/posts

👉 Display:

• First 5 posts

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✅ Exercise 11: Mini Project (Important)

👉 Build: Simple Contact Form System

Requirements:

• Use PHPMailer (via Composer)
• Form fields:
  • Name
  • Email
  • Message
• Send email on submit

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🧠 Bonus Challenges (Advanced)

🚀 Challenge 1:

Create your own PHP package and install it using Composer locally

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🚀 Challenge 2:

• Add version constraints in composer.json
• Try:

"phpmailer/phpmailer": "^6.0"

👉 Test:

• Run composer update

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🚀 Challenge 3:

• Delete vendor/
• Run:

composer install

👉 Understand:

• Difference between install vs update

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🎯 Tip (For You)

• 🧪 1 task per day