PHP Intro

PHP is a server-side scripting language designed for the web. A request hits your server, PHP runs, the browser receives HTML.

Where PHP fits

How a PHP request works

1. Browser asks for /page.php.
2. Apache / Nginx routes the request to PHP.
3. PHP executes the file, building HTML as it goes.
4. The HTML — never the PHP source — goes back to the browser.

The PHP you're learning

This tutorial targets PHP 8.x. Modern features include:

• Strict typing — typed properties, typed parameters, return types.
• Constructor property promotion — public function __construct(public string $name) {}.
• match expressions and structural enums.
• Named arguments — greet(name: 'Ada').
• Readonly properties (8.1+), readonly classes (8.2+).
• First-class callable syntax — $fn = strtoupper(...);.

Example

<?php
// PHP runs on the server, before HTML reaches the browser.
echo 'Hello from PHP ' . PHP_VERSION;

Exercise

Test yourself