Introduction to PHP: Understanding the Basics of Server-Side Scripting

💻 PHP (Hypertext Preprocessor)

🔍 What is PHP?

PHP (Hypertext Preprocessor) is a popular programming language used to create dynamic websites and web applications. It's a server-side language, which means it runs on a web server and generates HTML, CSS, and JavaScript code that's sent to a user's web browser.

💡 PHP in Simple Words:

• PHP is a programming language that runs on the web server.
• It helps create dynamic web pages that can change and adapt to user input.
• PHP is like a tool that makes your website more interactive, flexible, and fun!

🌐 What Can You Do with PHP?

• Create dynamic web pages that interact with databases
• Build e-commerce websites, blogs, and social media platforms
• Develop custom web applications and APIs
• Create login systems, forms, and surveys

⚙️ How Does PHP Work?

1. A user requests a web page from a website.
2. The web server receives the request and passes it to the PHP interpreter.
3. The PHP interpreter reads the PHP code and executes it.
4. The PHP code generates HTML, CSS, and JavaScript code.
5. The web server sends the generated code to the user's web browser.
6. The web browser renders the web page.

✏️ Defining Variables in PHP

To define a variable in PHP, use the $ symbol followed by the variable name:

$variable_name = value;

PHP Installation & Setup

To run PHP locally, you need a web server environment:

• Download and install XAMPP or WAMP

• Place your PHP files in the htdocs (XAMPP) directory

• Start Apache from the control panel

• Open browser and visit: http://localhost/filename.php

📊 Data Types in PHP

PHP is a dynamically-typed language. You don’t need to declare the data type — PHP decides it based on the value assigned.

📌 1. Boolean

• True or False values
• $bool = true;

📌 2. Integer

• Whole numbers (positive, negative, or zero)
• $int = 10;

📌 3. Float (Double)

• Decimal numbers
• $float = 10.5;

📌 4. String

• Sequence of characters (text)
• $str = "Hello World";

📌 5. Array

• Collection of values (indexed or associative)
• $arr = array("apple", "banana", "orange");

📌 6. Object

• Instance of a class (user-defined data type)
• $obj = new MyClass();

📌 7. NULL

• No value (empty or non-existent)
• $null = null;

📌 8. Resource

• Reference to an external resource (e.g. database connection)
• $conn = mysqli_connect(...);