PHP Intro

Introduction to PHP

PHP (Hypertext Preprocessor) is a widely-used server-side scripting language designed for web development. It allows developers to create dynamic content, interact with databases, and manage user sessions. PHP powers many popular websites and CMS platforms like WordPress, making it an essential tool for web developers.

Variables and Syntax

PHP variables start with a dollar sign $ and can hold different data types, including strings, integers, floats, booleans, arrays, and objects.

<?php
$name = "Master Geshu";
$age = 25;
$isActive = true;

echo "Welcome, $name!";
?>

PHP code is embedded within HTML using <?php ?> tags, making it flexible and easy to integrate with web pages.

Conditional Statements

PHP allows logical decisions using if, else, elseif, and switch statements.

<?php
$score = 85;
if ($score >= 90) {
    echo "Excellent!";
} elseif ($score >= 70) {
    echo "Good job!";
} else {
    echo "Needs improvement.";
}
?>

These statements control the flow of your program and help create dynamic responses based on user input or data.

Form Handling

PHP can process data submitted from HTML forms. Using $_POST or $_GET, developers can validate input and store or manipulate data.

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $username = $_POST["username"];
    echo "Hello, " . htmlspecialchars($username);
}
?>

Always sanitize user input to prevent security vulnerabilities such as XSS or SQL injection.

Database Connection

PHP interacts with databases like MySQL to store and retrieve data.

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "mydatabase";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>

Proper database connection and error handling ensures data security and smooth operation of web applications.

Conclusion

PHP is a powerful tool for creating dynamic websites and web applications. By understanding variables, syntax, conditional logic, form processing, and database connections, beginners can build robust, interactive sites and advance to frameworks like Laravel or CMS development.