Magic Methods (__get, __set, __call…)

Also Known As

TL;DR

Explanation

PHP magic methods include __construct/__destruct (lifecycle), __get/__set/__isset/__unset (property overloading), __call/__callStatic (method overloading), __toString (string casting), __invoke (callable objects), __clone (copy construction), and __wakeup/__sleep/__serialize/__unserialize (serialisation). Magic methods can dramatically simplify APIs but also hide bugs, complicate static analysis, and create security risks — __toString XSS, __wakeup object injection. Use them intentionally and document their behaviour clearly.

Common Misconception

Why It Matters

Common Mistakes

• __get() and __set() that silently create properties instead of throwing on undefined access — masks typos.
• __toString() that throws an exception — PHP does not allow exceptions from __toString() prior to PHP 8.
• __clone() not deep-copying nested objects — the cloned object shares references with the original.
• Heavy logic in __construct() — makes the class hard to instantiate in tests and violates single responsibility.

Code Examples

// __get silently swallows undefined property access:
class Config {
    public function __get(string $key): mixed {
        return $this->data[$key] ?? null; // Returns null for any typo — no error
    }
}
$config->databse_host; // Typo — silently returns null instead of error

class Collection {
    private array $items = [];

    public function __construct(array $items = []) {
        $this->items = $items;
    }

    // Called when accessing inaccessible/undefined property
    public function __get(string $name): mixed {
        return $this->items[$name] ?? null;
    }

    // Called when setting inaccessible/undefined property
    public function __set(string $name, mixed $value): void {
        $this->items[$name] = $value;
    }

    // Called by echo / string cast
    public function __toString(): string {
        return implode(', ', $this->items);
    }

    // Called by var_dump — PHP 8.2+
    public function __debugInfo(): array {
        return ['count' => count($this->items)];
    }

    // Called when object used as function
    public function __invoke(mixed $item): static {
        return new static([...$this->items, $item]);
    }
}

References

• ↗ https://www.php.net/manual/en/language.oop5.magic.php

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