02 Hello World

Goal

Write and run your first PHP script from a plain .php file, and understand the shape every PHP file shares.

Prerequisites

• Install PHP

The Shape of a PHP File

Every PHP file follows the same rule: everything outside <?php ... ?> is sent to the output as-is (that's the "HTML with escape hatches" model from the Introduction); everything inside is executed as code. A pure-logic file — like every file in this tier — usually opens with <?php and never bothers closing it, since there's no trailing HTML to resume.

<?php

echo "Hello, PHP!\n";

echo writes directly to output — no import, no main function, no entry-point boilerplate. The file itself is the entry point.

Code

Create hello.php:

<?php

echo "Hello, PHP!\n";

Run it:

php hello.php

Output:

Hello, PHP!

Checkpoint

Change the string, save, and re-run — no build step, no compile step. Edit, run, done.

Next

Continue to 03 Variables and Types.