MODULE 1: Introduction to PHP

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MODULE 1: Introduction to PHP - SitesByYogi

StreetGeek Academy · PHP Foundations

🧠 Module 1: Introduction to PHP & Setup

Objective: Understand what PHP is, where it runs, and how to set up your local development environment.

🔹 1. What PHP Is and How It Works

PHP (short for Hypertext Preprocessor) is a server-side scripting language designed
primarily for web development, but it’s also used as a general-purpose programming language.

PHP code runs on the server, not in your browser.
When a visitor requests a PHP page, the server processes the PHP code, generates HTML, and sends that HTML to the browser.
The browser never sees your PHP code—only the rendered result.

🧩 Example

<?php
echo "Hello, StreetGeek!";
?>

The server interprets this, sends only the text Hello, StreetGeek! to the browser, and hides the PHP logic from view.

🔹 2. PHP vs. HTML vs. JavaScript

Language	Runs On	Purpose	Example
HTML	Browser	Structure	Defines page layout (`<h1>Title</h1>`)
CSS	Browser	Style	Controls colors, fonts, spacing
JavaScript	Browser	Interactivity	Responds to user actions, fetches data dynamically
PHP	Server	Logic & Data	Fetches data, processes forms, connects to databases

💡 Think of it like this:
HTML is your skeleton, CSS is your clothes, JavaScript is your movements,
and PHP is your brain.

🔹 3. Server-side vs. Client-side

Type	Runs On	Example	Use Case
Client-side	User’s browser	JavaScript	Animations, instant form validation
Server-side	Web server	PHP	Database interaction, authentication, dynamic content

PHP runs before the page reaches the browser. JavaScript runs after the browser receives the page.

🔹 4. The LAMP Stack

The LAMP stack is a classic environment for running PHP websites:

L – Linux (Operating System)
A – Apache (Web Server)
M – MySQL (Database)
P – PHP (Scripting Language)

You can also run PHP on Windows (WAMP) or Mac (MAMP).

🔹 5. Installing LocalWP / XAMPP / MAMP

Option 1: 🧱 LocalWP (Recommended)

Easy setup for WordPress & PHP projects.
Download from localwp.com.
Create a new site → it automatically installs PHP, MySQL, and a local web server.

Option 2: ⚙️ XAMPP

Download from apachefriends.org.
Install and open the Control Panel.
Start Apache (web server) and MySQL (database).
Web root (default): C:\xampp\htdocs\
Example project path: C:\xampp\htdocs\php-basics\

Option 3: 🍎 MAMP (Mac)

Download from mamp.info.
Web directory: /Applications/MAMP/htdocs/

🔹 6. Writing Your First PHP Script

Create a folder called php-basics inside your web root directory:

LocalWP: use your site’s app/public folder.
XAMPP: htdocs/php-basics
MAMP: htdocs/php-basics

Inside it, create a file called index.php and add:

<?php
echo "Hello, StreetGeek!";
?>

Open your browser and visit:

http://localhost/php-basics/

✅ You should see: Hello, StreetGeek!

🔹 7. How the Server Interprets `.php` Files

When you request a PHP file like:

http://localhost/php-basics/index.php

Apache passes the file to the PHP interpreter.
PHP executes the code between <?php ... ?> tags.
The interpreter outputs HTML, which the server sends to your browser.

🧠 Example

<?php
$greeting = "StreetGeek Academy";
echo "<h1>Welcome to $greeting!</h1>";
?>

→ Browser output:

Welcome to StreetGeek Academy!

✅ Module 1 Deliverable & Assignment

Deliverable
Run your first PHP script that outputs:

<?php
echo "Hello, StreetGeek!";
?>

Assignment

Create a folder named php-basics.
Save your script as index.php.
Open it in the browser via http://localhost/php-basics/.
Take a screenshot of the output “Hello, StreetGeek!” for your course submission.

🧩 Module 1 Lab Sheet: Introduction to PHP

Objective: Get hands-on experience with PHP by setting up your environment,
writing your first script, and understanding how PHP interacts with HTML and the web server.

🧰 Lab Setup

Requirements:

Installed LocalWP / XAMPP / or MAMP
Code editor (Visual Studio Code recommended)
Web browser (Chrome, Edge, Firefox, etc.)

Folder Structure:

htdocs/
└── php-basics/
    └── index.php

🧪 Exercise 1: Hello, StreetGeek!

Goal: Write your first PHP program.

Open your php-basics folder.
Create a file named index.php.
Add this code:

<?php
echo "Hello, StreetGeek!";
?>

Open in your browser:

http://localhost/php-basics/

✅ Verify the page displays Hello, StreetGeek!

🧩 Exercise 2: Mixing PHP and HTML

Goal: Learn how PHP and HTML can work together.

<!DOCTYPE html>
<html>
<head>
    <title>StreetGeek Academy</title>
</head>
<body>
    <h1>Welcome to PHP Basics</h1>
    <p>
        <?php
            echo "This line is generated by PHP on " . date("l, F jS Y") . ".";
        ?>
    </p>
</body>
</html>

✅ The date changes dynamically each time you refresh.

🧩 Exercise 3: Embedding PHP Logic

Goal: Use PHP to generate different content dynamically.

<?php
$hour = date("H");
if ($hour < 12) {
    $greeting = "Good morning, StreetGeek!";
} elseif ($hour < 18) {
    $greeting = "Good afternoon, StreetGeek!";
} else {
    $greeting = "Good evening, StreetGeek!";
}
?>
<!DOCTYPE html>
<html>
<body>
    <h1><?php echo $greeting; ?></h1>
</body>
</html>

🧩 Exercise 4: Understanding PHP File Processing

Goal: Verify that PHP code is executed on the server.

Open your PHP page in the browser and right-click → View Page Source.
Notice that the PHP code (<?php ... ?>) does not appear—only the resulting HTML is shown.

🧩 Exercise 5: PHP Info

Goal: Learn about your server configuration.

Create a new file in php-basics called info.php.
Add this code:

<?php
phpinfo();
?>

Open in the browser:

http://localhost/php-basics/info.php

✅ You’ll see a detailed list of PHP settings, modules, and versions.

📝 Module 1 Quiz

#	Question	Options	Correct
1	What does PHP stand for?	a) Personal Home Page · b) PHP: Hypertext Preprocessor · c) Private Home Program	b
2	Where does PHP code execute?	a) In the browser · b) On the web server · c) On both	b
3	Which tag is used to start PHP code?	a) <php> · b) <?php · c) {php}	b
4	What is the file extension for PHP files?	a) .ph · b) .html · c) .php	c
5	What happens when you “View Page Source” of a PHP file?	a) You see all PHP code · b) You see only HTML output · c) You see server configuration	b

💪 Challenge Task – “Dynamic Greeting Page”

Objective: Build a simple PHP web page that changes its message based on the time of day.

Create a file greeting.php inside your php-basics folder.
Write code that:
- Displays a different greeting based on the current hour (date("H"))
- Shows today’s date and time using date()
- Includes some styled HTML (<h1>, <p>, <em>, etc.)

Target format:

Good afternoon, StreetGeek!
Today is Tuesday, October 27, 2025 — The perfect day to learn PHP.

Add CSS styling inline or via <style> tags and run it at:

http://localhost/php-basics/greeting.php

🧾 Submission Checklist

✅ Folder named php-basics
✅ index.php displays “Hello, StreetGeek!”
✅ info.php shows PHP configuration
✅ greeting.php outputs a time-based greeting
✅ Completed quiz answers

🏁 Completion Message: Once you finish, you’ve completed your first step toward PHP mastery.
In Module 2, you’ll learn the syntax and building blocks of PHP — variables, data types, and debugging with var_dump().