Last updated: Fri, 20 Jun 2008

Les classes et les objets (PHP 5)

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Introduction

En PHP 5, il y a un tout nouveau modèle objet. La gestion des objets en PHP a été complètement réécrite, permettant de meilleurs performances ainsi que plus de fonctionnalités.

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Last updated: Fri, 20 Jun 2008

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Les classes et les objets (PHP 5)

ranema at ubuntu dot polarhome dot com
30-Mar-2008 05:55


Just response to osculabond at gmail dot com:



Yeah, it's better way to emulate enum by using final classes, but I think it would be the best way if we used interfaces.

ranema at ubuntu dot polarhome dot com
30-Mar-2008 05:49


Sometimes you just forget to close handles, links, etc and sometimes you are just lazy to do that. PHP 5 OOP can do it automatically by using destructors:



<?php

class MySqlDriver {

   private $_Link;



   public function __construct( <...> ) {

      $this->_Link = mysql_connect( <...> );

   }



   // this will be called automatically at the end of scope

   public function __destruct() {

      mysql_close( $this->_Link );

   }

}



$_gLink = new MySqlDriver( <...> );

// and you don't need to close the link manually

?>

unclesam at yourshowcase dot com
25-Oct-2007 07:57


I discovered by experimentation (when I found it to be undocumented or mentioned in a forum), that it is possible to use anonymous class names when instantiating an object.



To wit:



class Something {

public $someproperty = "somevalue";

}

...

$class = "Something";

$object = new $class;

echo "{$object->someproperty}\n";



will show:



somevalue

bearachute at gmail dot com
27-Aug-2007 05:53


in addition to mail at touchmypixel dot com:



if methods aren't a concern, a great way to work with anonymous objects is to instantiate stdClass, which is php's base class. word up on the ECMAScript -- this works great with json!



<?php



$foo = new stdClass();

$foo->bar = 'string';

$foo->num = 10;



header('Content-type: application/json');

echo json_encode($foo);



?>

openspecies
16-Mar-2007 02:14


class enum {

  private $__this = array();

  function __construct()

  {

    $args = func_get_args();

    $i = 0;

    do{

      $this->__this[$args[$i]] = $i;

    } while(count($args) > ++$i);

  }

  public function __get($n){

    return $this->__this[$n];

  }

};

$days = new enum(

      "Sunday",

      "Monday",

      "Tuesday",

      "Wednesday",

      "Thursday",

      "Friday",

      "Saturday"

    );

$today = $days->Thursday;

echo $today;

mail at touchmypixel dot com
15-Feb-2007 06:05


An addition to the earlier post on creating anonymous objects.



You can make a quick anonmymous object just by using an unset variable as an object.



$foo->bar = "Hello World";

var_dump($foo->bar);



If you want to set it you can just use NULL or an empty string.



$foo = NULL;

$foo->bar = "Hello World";

var_dump($foo->bar);



This is extremely useful if you need to set a variable before using it, for example as a STATIC in a CLASS.



class MyClass {

  static $foo = NULL;

}

//

MyClass::$foo->bar = "Hello World";



You can also just create a NULL object and cast it as OBJECT.



$foo = (object) NULL;



This cannot be used when creating CLASS STATICs though. 



You can get some nice functionality out of this by combining some of the earlier examples into a simple function (thanks guys).



function object(){

    $o = (object) NULL;

    $n = func_num_args( ) ; 

    for ( $i = 0 ; $i < $n ; $i += 2 ) { 

       $o->{func_get_arg($i)} = func_get_arg($i + 1) ; 

    }

    return($o);

}



This lets you create an anonymous object, with variables already set, which is useful for single line creation, for example sending an object through to a function.



function say($obj){

    var_dump($obj->message);

}

say(object("message", "Hello World"));



Hope this helps for anyone looking how to create anonymous objects in PHP (anyone from the ECMAScript world - JavaScript or ActionScript!)

osculabond at gmail dot com
07-Oct-2006 08:20


A better way to simulate an enum in php5:



<?php

final class Days {

    const Sunday     = 0x00000001;

    const Monday     = 0x00000010;

    const Tuesday    = 0x00000100;

    const Wednesday = 0x00001000;

    const Thursday  = 0x00010000;

    const Friday    = 0x00100000;

    const Saturday  = 0x01000000;

    const Unknown    = 0x00000000;



    // ensures that this class acts like an enum

    // and that it cannot be instantiated

    private function __construct(){}

}

?>



This will allow you to do things like:



<?php

$day_to_email = Days::Thursday;



if($day_to_email == Days::Wednesday) echo "Wednesday<br />";

if($day_to_email == Days::Thursday) echo "Thursday<br />";

if($day_to_email == Days::Friday) echo "Friday<br />";

?>



Which would output:

Thursday



Or if you wanted to get a little fancier you could also do the following:



<?php

$days_to_email = Days::Monday | Days::Wednesday | Days::Friday;



if($days_to_email & Days::Monday) echo "Monday<br />";

if($days_to_email & Days::Tuesday) echo "Tuesday<br />";

if($days_to_email & Days::Wednesday) echo "Wednesday<br />";

if($days_to_email & Days::Thursday) echo "Thursday<br />";

if($days_to_email & Days::Friday) echo "Friday<br />";

?>



Which would output:

Monday

Wednesday

Friday

01-May-2006 03:06


Members can be added to instances on the fly.

Simply use

$apple= new fruit();

$pear=new fruit();

$apple->color='red';

$pear->smell='sweet';



and $apple only will contain a member (field) color, but $pear only will contain a field smell.



It is not clear however whether members an be added to the class at large on the fly.

S�b.
27-May-2005 06:50


We can't create easily anonymous objects like in JavaScript.

JS example :



    var o = {

        aProperty : "value",

        anotherProperty : [ "element 1", "element 2" ] } ;

    alert(o.anotherProperty[1]) ; // "element 2"



So I have created a class Object :



    class Object {

        function __construct( ) {

            $n = func_num_args( ) ;

            for ( $i = 0 ; $i < $n ; $i += 2 ) {

                $this->{func_get_arg($i)} = func_get_arg($i + 1) ;

            }

        }

    }



    $o = new Object(

        'aProperty', 'value',

        'anotherProperty', array('element 1', 'element 2')) ;

    echo $o->anotherProperty[1] ; // "element 2"



You must feel free to make it better :)

29-Mar-2005 01:21


There are 3 simple, and utterly annoying problems with your classes (not because of how you want them to work, but because how the Zend II engine handles them):



1) You cannot type hint string or int/integer in a method signature. This is incredibly annoying that the Zend II engine doesn't support it, but there are workarounds.

2) Supplying null in a method signature for a default value means that you will not accept any null value for that parameter. (therefore the method doesn't need to check if the parameters are null anyway).

3) Sadly, overriding methods is only possible with the Zend II engine via Inheritance or Polymorphism, ( and __construct() can only be defined within a class). If you want to override a method in the same class, my suggestion is to provide the method signature with a $flag = null variable, which you call a SWITCH on to pick what the data should do.



==============================================

Other than the afformentioned, the Zend II engine works very similarly to Java, which has made PHP much more versatile and robust in version 5. Thank you again Zend!

spam at afoyi dot com
21-Mar-2005 02:18


You can call a function defined in an inherited class from the parent class. This works in both PHP 4.3.6 and 5.0.0:



<?php



class p {

    

    function p() {

        print "Parent's constructor\n";

    }

    

    function p_test() {

        print "p_test()\n";

        $this->c_test();

    }

}



class c extends p {

    

    function c() {

        print "Child's constructor\n";

        parent::p();

    }

    

    function c_test() {

        print "c_test()\n";

    }

}



$obj = new c;

$obj->p_test();



?>



Outputs:



Child's constructor

Parent's constructor

p_test()

c_test()

farzan at ifarzan dot com
06-Oct-2004 01:04


PHP 5 is very very flexible in accessing member variables and member functions. These access methods maybe look unusual and unnecessary at first glance; but they are very useful sometimes; specially when you work with SimpleXML classes and objects. I have posted a similar comment in SimpleXML function reference section, but this one is more comprehensive.



I use the following class as reference for all examples:

<?

class Foo {

    public $aMemberVar = 'aMemberVar Member Variable';

    public $aFuncName = 'aMemberFunc';

    

    

    function aMemberFunc() {

        print 'Inside `aMemberFunc()`';

    }

}



$foo = new Foo;

?>



You can access member variables in an object using another variable as name:

<?

$element = 'aMemberVar';

print $foo->$element; // prints "aMemberVar Member Variable"

?>



or use functions:

<?

function getVarName()

{ return 'aMemberVar'; }



print $foo->{getVarName()}; // prints "aMemberVar Member Variable"

?>



Important Note: You must surround function name with { and } or PHP would think you are calling a member function of object "foo".



you can use a constant or literal as well:

<?

define(MY_CONSTANT, 'aMemberVar');

print $foo->{MY_CONSTANT}; // Prints "aMemberVar Member Variable"

print $foo->{'aMemberVar'}; // Prints "aMemberVar Member Variable"

?>



You can use members of other objects as well:

<?

print $foo->{$otherObj->var};

print $foo->{$otherObj->func()};

?>



You can use mathods above to access member functions as well:

<?

print $foo->{'aMemberFunc'}(); // Prints "Inside `aMemberFunc()`"

print $foo->{$foo->aFuncName}(); // Prints "Inside `aMemberFunc()`"

?>

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Last updated: Fri, 20 Jun 2008