
I.		Na początek
II.		Instalacja i konfiguracja
III.		Opis języka
IV.		Bezpieczeństwo
V.		Możliwości
VI.		Opis funkcji
VII.		Zend API
VIII.		PHP API: Interfejs rozszerzeń
X.		Dodatki

Manual PHP

Zapraszam do korzystania z zamieszczonego przeze mnie manuala php. Mam nadzieję, że ta jego kopia przyda się zarówno profesjonalnym programistą, jak i początkującym twórcą skryptów PHP.

Autorzy

Mehdi Achour,

Friedhelm Betz,

Antony Dovgal,

Nuno Lopes,

Philip Olson,

Georg Richter,

Damien Seguy,

Jakub Vrana,

I kilka innych

Redakcja:

Gabor Hojtsy,

Marcin Dąbrowski, Michał Grzechowiak, Leszek Krupiński, Adam Major, Paweł Paprota, Michał Pena, Sławomir Pucia, Jarek Tabor, Tomasz Wójtowicz,

Podręcznik PHP
Poprzedni	Rozdział 19. Classes and Objects (PHP 5)	Następny

Magic Methods

The function names __construct, __destruct (see Constructors and Destructors), __call, __get, __set (see Overloading), __sleep, __wakeup, and __toString are magical in PHP classes. You cannot have functions with these names in any of your classes unless you want the magic functionality associated with them.

Uwaga!

PHP reserves all function names starting with __ as magical. It is recommended that you do not use function names with __ in PHP unless you want some documented magic functionality.

`sleep` and `wakeup`

serialize() checks if your class has a function with the magic name __sleep. If so, that function is executed prior to any serialization. It can clean up the object and is supposed to return an array with the names of all variables of that object that should be serialized.

The intended use of __sleep is to close any database connections that the object may have, commit pending data or perform similar cleanup tasks. Also, the function is useful if you have very large objects which do not need to be saved completely.

Conversely, unserialize() checks for the presence of a function with the magic name __wakeup. If present, this function can reconstruct any resources that the object may have.

The intended use of __wakeup is to reestablish any database connections that may have been lost during serialization and perform other reinitialization tasks.

`__toString`

The __toString method allows a class to decide how it will react when it is converted to a string.

Przykład 19-25. Simple example


<?php
// Declare a simple class
class TestClass
{
    public $foo;

    public function __construct($foo) {
        $this->foo = $foo;
    }

    public function __toString() {
        return $this->foo;
    }
}

$class = new TestClass('Hello');
echo $class;
?>

Powyższy przykład wyświetli:

Hello

It is worth noting that the __toString method will only be called when it is directly combined with echo() or print().

Przykład 19-26. Cases where __toString is called


<?php
// __toString called
echo $class;

// __toString called (still a normal parameter for echo)
echo 'text', $class;

// __toString not called (concatenation operator used first)
echo 'text' . $class;

// __toString not called (cast to string first)
echo (string) $class;

// __toString not called (cast to string first)
echo "text $class";
?>

Poprzedni	Spis treści	Następny
Patterns	Początek rozdziału	Final Keyword

print 'księgowość internetowa 1171501919' . "\n"; print 'oc ubezpieczenia 1171501682' . "\n"; print 'ubezpieczenia samochodu kalkulator 1171501691' . "\n"; print 'sala weselna Warszawa 1171501846' . "\n";