PHP

PHP Basics

PHP Data

Control Flow

PHP Functions

PHP Arrays

PHP Forms

PHP Advanced

Cookies & Sessions

Filters & JSON

PHP Exceptions

PHP OOP

MySQL with PHP

PHP and XML

AJAX with PHP

PHP Introduction

🔹 What is PHP?

PHP stands for Hypertext Preprocessor. It is a server-side scripting language used primarily for web development, but it can also be used as a general-purpose programming language.

PHP code runs on the server, and the result is sent to the browser as plain HTML.

🔹 Why Learn PHP?

Easy to learn and use
Runs on all major platforms (Windows, Linux, macOS)
Compatible with all major databases (MySQL, PostgreSQL, etc.)
Used in popular platforms like WordPress, Drupal, Magento
Open-source and well-supported by the community

🔹 What Can PHP Do?

✅ Generate dynamic page content
✅ Handle form data
✅ Create, open, read, write, delete files on the server
✅ Send and receive cookies
✅ Connect to databases
✅ Manage user sessions
✅ Encrypt data

🔹 PHP Syntax Example

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

🔸 Explanation:

PHP code is enclosed in <?php ... ?> tags
echo is used to output text
Statements end with a semicolon ;

🔹 How PHP Works

Client requests a PHP file (e.g., index.php)
Web server (e.g., Apache) processes the PHP code
The server sends the output (usually HTML) to the client’s browser

🔹 PHP File Structure

File extension: .php
Can contain HTML + PHP code

Example:

<!DOCTYPE html>
<html>
<body>

<h1>My first PHP page</h1>
<?php
echo "Hello from PHP!";
?>

</body>
</html>

Practice Questions

Q1. Write a PHP program to display your name.

Example Output:
My name is John.

Q2. Write a PHP program to add two numbers and display the result.

Example Output:
Sum: 15

Q3. Write a PHP program that uses variables to store a name and concatenate it with a welcome message.

Example Output:
Welcome, Alice

Q4. Write a PHP program to check if a person is eligible to vote using an if-else condition.

Condition: Age should be 18 or above.
Example Output:
Adult

Q5. Write a PHP program to store colors in an array and display them one by one using a foreach loop.

Example Output:

Red Green Blue