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    get_object_vars

    (PHP 4, PHP 5, PHP 7, PHP 8)

    get_object_vars — Restituisce le proprietà dell'oggetto dato

    Descrizione

    get_object_vars(object $object): array

    Restituisce le proprietà non-statiche accessibili dell'object dato in base all'ambito.

    Elenco dei parametri

    object

    Un'istanza dell'oggetto.

    Valori restituiti

    Restituisce un array associativo delle proprietà non-statiche accessibili dell'oggetto definito per l'object specificato nell'ambito. Se ad una proprietà non è stato assegnato un valore, essa verrà restituita con un valore null.

    Log delle modifiche

    Versione Descrizione
    5.3.0 Questa funzione ora restituisce null se object non è un oggetto. In precedenza veniva restituito false.

    Esempi

    Example #1 Uso di get_object_vars()

    <?php

    class foo {
    private     $a;
    public     $b = 1;
    public     $c;
    private     $d;
    static     $e;

    public function     test() {
    var_dump(get_object_vars($this));
    }
    }

    $test = new foo;
    var_dump(get_object_vars($test));

    $test->test();

    ?>

    Il precedente esempio visualizzerà:

    array(2) {
  ["b"]=>
  int(1)
  ["c"]=>
  NULL
}
array(4) {
  ["a"]=>
  NULL
  ["b"]=>
  int(1)
  ["c"]=>
  NULL
  ["d"]=>
  NULL
}

    Vedere anche:

    add a note add a note

    User Contributed Notes 5 notes

    up
    54
    fmmarzoa at librexpresion dot org
    20 years ago
    You can still cast the object to an array to get all its members and see its visibility. Example:

    <?php

    class Potatoe {
        public     $skin;
        protected     $meat;
        private     $roots;

        function     __construct ( $s, $m, $r ) {
                $this->skin = $s;
                $this->meat = $m;
                $this->roots = $r;
        }
    }

    $Obj = new Potatoe ( 1, 2, 3 );

    echo     "<pre>\n";
    echo     "Using get_object_vars:\n";

    $vars = get_object_vars ( $Obj );
    print_r ( $vars );

    echo     "\n\nUsing array cast:\n";

    $Arr = (array)$Obj;
    print_r ( $Arr );

    ?>

    This will returns:

    Using get_object_vars:
    Array
    (
        [skin] => 1
    )

    Using array cast:
    Array
    (
        [skin] => 1
        [ * meat] => 2
        [ Potatoe roots] => 3
    )

    As you can see, you can obtain the visibility for each member from this cast. That which seems to be spaces into array keys are '\0' characters, so the general rule to parse keys seems to be:

    Public members: member_name
    Protected memebers: \0*\0member_name
    Private members: \0Class_name\0member_name

    I've wroten a obj2array function that creates entries without visibility for each key, so you can handle them into the array as it were within the object:

    <?php

    function obj2array ( &$Instance ) {
            $clone = (array) $Instance;
            $rtn = array ();
            $rtn['___SOURCE_KEYS_'] = $clone;

        while ( list (    $key, $value) = each ($clone) ) {
                $aux = explode ("\0", $key);
                $newkey = $aux[count($aux)-1];
                $rtn[$newkey] = &$rtn['___SOURCE_KEYS_'][$key];
        }

        return     $rtn;
    }

    ?>

    I've created also a <i>bless</i> function that works similar to Perl's bless, so you can further recast the array converting it in an object of an specific class:

    <?php

    function bless ( &$Instance, $Class ) {
        if ( ! (    is_array ($Instance) ) ) {
            return     NULL;
        }

            // First get source keys if available
            if ( isset ($Instance['___SOURCE_KEYS_'])) {
                $Instance = $Instance['___SOURCE_KEYS_'];
        }

            // Get serialization data from array
            $serdata = serialize ( $Instance );

        list (    $array_params, $array_elems) = explode ('{', $serdata, 2);
        list (    $array_tag, $array_count) = explode (':', $array_params, 3 );
            $serdata = "O:".strlen ($Class).":\"$Class\":$array_count:{".$array_elems;

            $Instance = unserialize ( $serdata );
        return     $Instance;
    }
    ?>

    With these ones you can do things like:

    <?php

    define    ("SFCMS_DIR", dirname(__FILE__)."/..");
    require_once (    SFCMS_DIR."/Misc/bless.php");

    class     Potatoe {
        public     $skin;
        protected     $meat;
        private     $roots;

        function     __construct ( $s, $m, $r ) {
                $this->skin = $s;
                $this->meat = $m;
                $this->roots = $r;
        }

        function     PrintAll () {
            echo     "skin = ".$this->skin."\n";
            echo     "meat = ".$this->meat."\n";
            echo     "roots = ".$this->roots."\n";
        }
    }

    $Obj = new Potatoe ( 1, 2, 3 );

    echo     "<pre>\n";
    echo     "Using get_object_vars:\n";

    $vars = get_object_vars ( $Obj );
    print_r ( $vars );

    echo     "\n\nUsing obj2array func:\n";

    $Arr = obj2array($Obj);
    print_r ( $Arr );

    echo     "\n\nSetting all members to 0.\n";
    $Arr['skin']=0;
    $Arr['meat']=0;
    $Arr['roots']=0;

    echo     "Converting the array into an instance of the original class.\n";
    bless ( $Arr, Potatoe );

    if (     is_object ($Arr) ) {
        echo     "\$Arr is now an object.\n";
        if (     $Arr instanceof Potatoe ) {
            echo     "\$Arr is an instance of Potatoe class.\n";
        }
    }

    $Arr->PrintAll();

    ?>
    up
    9
    Trismegiste
    2 years ago
    Please be aware of hidden behaviors with uninitialised properties. The note explains : « Uninitialized properties are considered inaccessible, and thus will not be included in the array. » but that's not entirely true in PHP 8.1. It depends if the property is type-hinted or not.

    <?php

    class Example
    {
      public     $untyped;
      public     string $typedButNotInitialized;
      public ?    string $typedOrNullNotInitialized;
      public ?    string $typedOrNullWithDefaultNull = null;
    }

    var_dump(get_object_vars(new Example()));
    ?>

    will print :

    array(2) {
      ["untyped"]=>
      NULL
      ["typedOrNullWithDefaultNull"]=>
      NULL
    }

    As you can see, only "untyped" and "typedOrNullWithDefaultNull" properties are dumped with get_object_vars(). You may encounter problems when migrating old source code and adds carelessly types everywhere without proper initialisation (or default) and assuming it defaults to NULL like old code does.

    Hope this helps
    up
    4
    marcus at marcusball dot me
    3 years ago
    When dealing with a very large quantity of objects, it is worth noting that using `get_object_vars()` may drastically increase memory usage.

    If instantiated objects only use predefined properties from a class then PHP can use a single hashtable for the class properties, and small memory-efficient arrays for the object properties:

    If a class is defined with three properties ($foo, $bar, and $baz), "PHP no longer has to store the data in a hashtable, but instead can say that $foo is proprety 0, $bar is proprety 1, $baz is property 2 and then just store the properties in a three-element C array. This means that PHP only needs one hashtable in the class that does the property-name to offset mapping and uses a memory-efficient C-array in the individual objects."

    However, if you call `get_object_vars()` on an object like this, then PHP WILL build a hashtable for the individual object. If you have a large quantity of objects, and you call `get_object_vars()` on all of them, then a hashtable will be built for each object, resulting in a lot more memory usage. This can be seen in this bug report: https://bugs.php.net/bug.php?id=79392

    The effects of this can be seen in this example:

    <?php
    class Example {
        public     $foo;
        public     $bar;
        public     $baz;
    }

    function     printMem($label) {
            $usage = memory_get_usage();
        echo     sprintf('%s: %d (%.2f MB)', $label, $usage, $usage / 1000000) . PHP_EOL;
    }

    printMem('start');

    $objects = [];
    for (    $i = 0; $i < 20000; $i++) {
            $obj = new Example;
            $obj->foo = bin2hex(random_bytes(5));
            $obj->bar = bin2hex(random_bytes(5));
            $obj->baz = bin2hex(random_bytes(5));
            $objects[] = $obj;
    }

    printMem('before get_object_vars');

    // Clone each object, and get the vars on the clone
    foreach ($objects as $obj) {
            $c = clone $obj;
            $vars = get_object_vars($c);

            // Accessing and modifying the original object is fine.
            foreach ($vars as $var => $val) {
                $obj->{$var} = strrev($val);
        }
    }

    printMem('get_object_vars using clone');

    // Get the vars on each object directly
    foreach ($objects as $obj) {
            $vars = get_object_vars($obj);

            // The memory is used even if you do not modify the object.
    }

    printMem('get_object_vars direct access');
    ?>

    The output of this is:

        start: 405704 (0.41 MB)
        before get_object_vars: 6512416 (6.51 MB)
        get_object_vars using clone: 6033408 (6.03 MB)
        get_object_vars direct access: 13553408 (13.55 MB)

    In short, if you are using classes to avoid additional memory usage associated with hashtables (like in associative arrays), be aware that `get_object_vars()` will create a hashtable for any object passed to it.

    This appears to be present in all versions of PHP; I've tested it on PHP 5, 7, and 8.

    Quotes are from Nikic's blog posts on arrays and hashtable memory usage, and Github gist "Why objects (usually) use less memory than arrays in PHP".
    up
    7
    niemans at pbsolo dot nl
    3 years ago
    You can use an anonymous class to return public variables from inside the class:

    public function getPublicVars () {
        $me = new class {
            function getPublicVars($object) {
                return get_object_vars($object);
            }
        };
        return $me->getPublicVars($this);
    }

    Test script:

    class Test {
        protected $protected;
        public    $public;
        private   $private;
        public function getAllVars () {
            return call_user_func('get_object_vars', $this);
        }
        public function getPublicVars () {
            $me = new class {
                function getPublicVars($object) {
                    return get_object_vars($object);
                }
            };
            return $me->getPublicVars($this);
        }
    }

    $test = new Test();
    print_r(get_object_vars($test)); // array("public" => NULL)
    print_r($test->getAllVars());   // array("protected" => NULL, "public" => NULL, "private" => NULL)
    print_r($test->getPublicVars()); // array("public" => NULL)
    up
    5
    Fabien Haddadi
    12 years ago
    It seems like there's no function that determines all the *static* variables of a class.

    I've come out with this one as I needed it in a project:

    <?php
    function get_class_static_vars($object) {
         return     array_diff(get_class_vars(get_class($object)), get_object_vars($object));
    }
    ?>

    It relies on an interesting property: the fact that get_object_vars only returns the non-static variables of an object.
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