PHP Environment Setup

Web Server Requirements

PHP code needs a web server that knows how to hand .php requests to the PHP interpreter — Apache and Nginx are the two most common.

Rather than installing and configuring each piece separately, most beginners install an all-in-one bundle like XAMPP or MAMP, which packages a web server, PHP, and MySQL together.

Example: Web Server Requirements

<?php
// Declare `$server`, set to `$_SERVER['SERVER_SOFTWARE'] ?? 'PHP CLI'`
$server = $_SERVER['SERVER_SOFTWARE'] ?? 'PHP CLI';
// Print `"This request was handled by: " . $server` to the output
echo "This request was handled by: " . $server;
?>

Installing PHP

You can install PHP directly on your machine via your OS package manager (or an installer bundle), or skip local setup entirely and write PHP in a browser-based playground while you're still learning the syntax — useful when you just want to test a snippet without standing up a full server.

Example: Installing PHP

<?php
// Run this file with: php filename.php  (or via a browser-based playground)
echo "PHP is installed and running.";
?>

Writing Your Code

Save your code in a plain text file with a .php extension so the web server routes it to the PHP interpreter instead of serving it as a static file.

Inside that file, PHP code lives between <?php and ?> tags; everything outside those tags is passed through as-is, which is what lets you mix PHP and HTML freely.

Example: Writing Your Code

<?php
// Print "This runs inside the tags." to the output
echo "This runs inside the tags.";
?>
<p>This HTML passes through untouched.</p>

Running PHP Locally

You can run a .php file two ways: through a configured web server (visiting it in a browser), or directly from a terminal with php filename.php, which executes the script and prints its output to the terminal — handy for quick tests without touching a browser at all.

Example: Running PHP Locally

<?php
// Run with: php filename.php
echo "Printed directly to the terminal, no browser needed.";
?>

Verifying the Version

Run php -v in a terminal to see which PHP version is installed. Aim for PHP 7.4 or newer: modern syntax like arrow functions, typed properties, and the null coalescing assignment operator (??=) simply won't parse on older interpreters.

Example: Verifying the Version

<?php
// Print `"PHP version: " . PHP_VERSION` to the output
echo "PHP version: " . PHP_VERSION;
// Print `PHP_VERSION_ID >= 70400 ? "\nModern syntax supported." : "\nUpgrade recommended."` to the output
echo PHP_VERSION_ID >= 70400 ? "\nModern syntax supported." : "\nUpgrade recommended.";
?>