031.php: A Quick Guide to PHP Basics

Introduction

PHP is a widely used server-side scripting language that powers many websites. It runs on a web server and is embedded in HTML to generate dynamic pages.

What is PHP?

PHP stands for PHP: Hypertext Preprocessor. It is a scripting language that runs on the server, processes data, and sends HTML to the browser. It is open source, easy to learn, and integrates well with popular web servers.

Why PHP still matters

• Large ecosystem and hosting support
• WordPress and many CMS run on PHP
• Simple syntax for beginners

Where PHP runs

Typically with Apache or Nginx, often using PHP-FPM. It can be run locally or in the cloud; many shared hosting plans support PHP by default.

Getting Started with PHP

Installing PHP

Choose a method: install PHP locally, use a package like XAMPP/MAMP, or run via Docker. Ensure you have PHP installed by running php -v.

Writing your first script

Create a file named hello.php with:

<?php
echo 'Hello, world!';
?>

Save and run it via your web server. You should see Hello, world! in your browser.

Core PHP Concepts

Variables and data types

PHP uses a $ prefix for variables. Common types: strings, integers, floats, booleans, arrays, objects.

Operators and control structures

Use if, else, for, foreach, while, and switch for logic.

Arrays and loops

Arrays hold lists of values; foreach is handy for iterating.

Functions

Functions group reusable code. Define with function name($args) { ... }.

Building a Simple Script

Hello, World in PHP

A minimal script that prints text to the browser.

<?php
echo 'Hello, world!';
?>

Simple form handling

A tiny example shows how to read user input from a form and display a safe response.

<form method='post' action=''>
  <input type='text' name='name' placeholder='Your name'>
  <button type='submit'>Submit</button>
</form>

<?php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
  $name = $_POST['name'] ?? '';
  echo 'Nice to meet you, ' . htmlspecialchars($name) . '!';
}
?>

Common Pitfalls and Best Practices

Security basics

Always validate and sanitize input; escape output with htmlspecialchars; use prepared statements to avoid SQL injection.

Error handling and debugging

Display errors in development; log errors in production; use errorreporting and iniset to tune behavior.

Performance tips

Use caching, enable opcache, minimize IO, and optimize database queries.

Conclusion

PHP remains a solid choice for server-side web development. Start with small scripts, practice with forms, and explore the ecosystem to build dynamic websites confidently.