Variables

Variables in PHP: naming, assignment, type juggling, and real examples.

On this page

Creating Variables

Variables start with $. PHP is dynamically typed, so the type can change based on assigned value.

<?php
$age = 12;              // int
$price = 19.99;         // float
$name = 'Ozan';       // string
$isActive = true;       // bool

PHP can automatically convert types in some operations. This is powerful, but can create bugs if you assume strict types everywhere.

<?php
echo 10 + '5';        // 15 (string '5' becomes number)
echo '10' . 5;        // '105' (string concatenation)

Use ?? to set safe defaults when a value may be missing (common for request data).

<?php
$q = $_GET['q'] ?? '';
$page = (int)($_GET['page'] ?? 1);

Use descriptive names and consistent style (e.g., camelCase for variables). Avoid cryptic names like $x unless it's a short loop variable.

<?php
$totalPrice = 0;
$itemsCount = 0;

During development, you can inspect values using var_dump or print_r. Don't expose these in production responses.

<?php
var_dump($page);