PHP for Beginners: The Basics

PHP Syntax and Variables

1 min read Last updated 44 minutes ago

PHP runs on the server and produces output that the browser receives as HTML.

PHP tags

PHP code lives inside <?php ?> tags:

php

<?php
echo "Hello from PHP!";

Variables

Variables start with $ and don't need a declared type:

php

<?php
$name = "TutsFx";
$year = 2025;
$price = 19.99;
$isFree = true;

Data types

PHP has these core types:

php

$string  = "Hello";
$integer = 42;
$float   = 3.14;
$boolean = true;
$array   = ['red', 'green', 'blue'];
$null    = null;

String interpolation

Double-quoted strings interpolate variables:

php

<?php
$user = "Ada";
echo "Welcome back, {$user}!";
// Output: Welcome back, Ada!

Single quotes do not interpolate:

php

echo 'Welcome back, {$user}!';
// Output: Welcome back, {$user}!

Mixing PHP with HTML

html

<!DOCTYPE html>
<html>
<body>
    <h1><?php echo "Dynamic heading"; ?></h1>
    <p><?php echo date('Y'); ?></p>
</body>
</html>

Security first

Never trust user input. Anything from $_GET, $_POST or $_COOKIE must be escaped before output — use htmlspecialchars() or a framework's built-in escaping.

Debugging

Use var_dump() to inspect values while learning:

php

<?php
$items = ['a', 'b'];
var_dump($items);

Next Arrays and Control Flow