Magic methods are special methods with double-underscore prefixes that PHP calls automatically in response to certain actions. They allow you to define custom behaviour for common operations.
__toString() — called when an object is cast to string.__get($name) / __set($name, $value) — called for inaccessible property access.__isset($name) / __unset($name) — called by isset() and unset() on inaccessible properties.__invoke() — called when the object is used as a function.<?php
class MagicBox
{
private array $data = [];
// __set: called when assigning to inaccessible property
public function __set(string $name, mixed $value): void
{
echo "__set: $name = " . var_export($value, true) . "
";
$this->data[$name] = $value;
}
// __get: called when reading an inaccessible property
public function __get(string $name): mixed
{
echo "__get: $name
";
return $this->data[$name] ?? null;
}
// __isset: called by isset() / empty() on inaccessible property
public function __isset(string $name): bool
{
return isset($this->data[$name]);
}
// __unset: called by unset() on inaccessible property
public function __unset(string $name): void
{
unset($this->data[$name]);
}
// __toString: called when object is cast/echoed as string
public function __toString(): string
{
return json_encode($this->data, JSON_PRETTY_PRINT);
}
// __invoke: called when object is used as function
public function __invoke(string $key): mixed
{
return $this->data[$key] ?? null;
}
}
$box = new MagicBox();
$box->name = 'Alice'; // calls __set
$box->email = 'alice@example.com';
echo $box->name; // calls __get
echo isset($box->email) ? 'set' : 'not set'; // calls __isset
echo $box; // calls __toString
echo $box('name'); // calls __invoke
Tip: Use magic methods sparingly. __get() and __set() bypass PHP's type system and IDE autocompletion. Prefer explicit typed properties and methods for code that benefits from static analysis.