Class 1:
Introduction to PHP
Objective:
- Understand
what PHP is and its role in web development.
- Set
up the PHP development environment.
Outcome:
- Students
will be able to describe PHP’s purpose in web development.
- Students
will set up a local development environment with XAMPP/WAMP/MAMP.
- Students
will create and run a basic PHP script using phpinfo() to verify the
installation.
1. What
is PHP?
- Definition: PHP
stands for "PHP: Hypertext Preprocessor." It's a widely-used,
open-source server-side scripting language designed primarily for web
development.
- Purpose
of PHP in Web Development:
- PHP
is embedded within HTML to create dynamic content, meaning it can
interact with databases, generate pages dynamically based on user
actions, handle forms, and more.
- It
enables websites to offer more interactivity, like login systems,
shopping carts, forums, and other personalized experiences.
- Advantages
of PHP:
- Open-Source:
PHP is free to use, which makes it accessible to many developers.
- Server-Side
Execution: PHP code is executed on the server, making
it secure from the user’s point of view.
- Cross-Platform:
PHP can run on various operating systems, including Windows, macOS, and
Linux.
- Easy
Integration with Databases: PHP can connect to
different types of databases, with MySQL being the most popular in PHP
development.
2. Role
of PHP in Web Development
- PHP
is primarily used to develop the server-side (backend) of a web
application.
- How
PHP Works:
- When
a user requests a PHP page, the web server processes the PHP code,
generates HTML output, and sends this output back to the user's browser.
- PHP
allows us to interact with databases to fetch or store data.
- Common
Uses of PHP:
- Dynamic
Content Creation: Displaying different content based on user
interactions.
- Form
Handling: Collecting and processing user data through forms.
- Session
Management: Managing user sessions for login and personalized content.
- Database
Interaction: Retrieving and storing information from/to databases.
3.
Setting Up the PHP Development Environment
To run PHP code, we need a server
environment. The easiest way to set this up locally is by using software like XAMPP,
WAMP, or MAMP.
Why
XAMPP, WAMP, or MAMP?
These tools bundle the Apache
server, MySQL (database), and PHP (language interpreter) together, creating a
simple, one-click solution to set up a local server on your computer.
Steps to
Install XAMPP (for Windows)
1. Download
XAMPP:
o
Go to the XAMPP website.
o
Choose the XAMPP installer for your operating
system (usually Windows, macOS, or Linux).
2. Install
XAMPP:
o
Open the downloaded file and follow the on-screen
instructions to install.
o
Choose components to install (select Apache, MySQL,
and PHP by default).
o
Select the installation directory (default is C:\xampp
on Windows).
3. Start
Apache and MySQL:
o
Open the XAMPP Control Panel.
o
Click “Start” for Apache and MySQL to launch the
web server and database server.
o
Ensure both services are running by checking for
green indicators.
Using
XAMPP on Other Operating Systems:
- macOS: Use
MAMP, which works similarly to XAMPP but is optimized for macOS.
- Linux: Use
XAMPP or LAMP (Linux + Apache + MySQL + PHP).
4.
Testing the PHP Installation
Once XAMPP is installed and
running, you can test your PHP setup by creating a simple PHP script.
Steps to
Create and Run a PHP Script
1. Locate
the htdocs Folder:
o
Navigate to the htdocs folder inside your XAMPP
directory (usually C:\xampp\htdocs on Windows).
o
This is the default folder where all your PHP files
should be saved to run in the browser.
2. Create a
New PHP File:
o
Inside the htdocs folder, create a new file named test.php.
o
Open this file in a text editor and add the
following code:
php
Copy code
<?php
// This
script displays information about the PHP installation.
phpinfo();
?>
o
The phpinfo() function outputs information about
PHP’s configuration, which is useful to verify that PHP is working correctly.
3. Run the
Script:
o
Open your web browser.
o
Type http://localhost/test.php in the address bar
and press Enter.
o
If PHP is installed correctly, you should see a
page displaying details about your PHP configuration.
5.
Explanation of phpinfo() Function
- Purpose
of phpinfo():
- This
function provides detailed information about the PHP environment,
including the PHP version, configuration settings, available extensions,
and server information.
- It's
helpful for debugging and for checking whether PHP and its components
(like extensions) are installed and configured correctly.
6.
Practical Tips
- Saving
PHP Files: Always save PHP files with a .php extension.
- Running
PHP Scripts: PHP files must be executed on a server (like
Apache) and accessed via localhost in a browser to process PHP code.
Double-clicking a .php file won’t work as the PHP code won’t be
interpreted without a server.
- Error
Checking: If you don’t see the phpinfo() page or
encounter an error, check:
- That
Apache is running in the XAMPP Control Panel.
- The
file path is correct and the .php extension is used.
Recap and
Summary
1. PHP
Overview:
o
PHP is a server-side scripting language used to
create dynamic, interactive websites.
o
It integrates well with HTML and databases,
enabling features like user login systems, data storage, and personalized
content.
2. Setting
Up Development Environment:
o
Using XAMPP, WAMP, or MAMP simplifies the
installation of Apache, MySQL, and PHP, creating a local server environment for
PHP development.
3. Creating
and Testing PHP Scripts:
o
A basic phpinfo() script verifies that PHP is
installed and running correctly.
Class
Assignment
1. Install
XAMPP on your computer (or MAMP for macOS users).
2. Create a
file named hello.php in the htdocs directory and add the following code:
php
Copy code
<?php
echo "Hello,
PHP World!";
?>
3. Open your
browser and access http://localhost/hello.php to see the output.
4. Submit a
screenshot of the "Hello, PHP World!" output as confirmation of setup
completion.
These steps introduce students to
PHP, help them understand its role, and ensure they have a running PHP
environment for future development tasks.