get_class_vars
Returns an associative array of declared properties visible from the current scope, with their default value. The resulting array elements are in the form of varname => value . In case of an error, it returns false .
Examples
Example #1 get_class_vars() example
var $var1 ; // this has no default value.
var $var2 = «xyz» ;
var $var3 = 100 ;
private $var4 ;
// constructor
function __construct () // change some properties
$this -> var1 = «foo» ;
$this -> var2 = «bar» ;
return true ;
>
$class_vars = get_class_vars ( get_class ( $my_class ));
foreach ( $class_vars as $name => $value ) echo » $name : $value \n» ;
>
The above example will output:
var1 : var2 : xyz var3 : 100
Example #2 get_class_vars() and scoping behaviour
function format ( $array )
return implode ( ‘|’ , array_keys ( $array )) . «\r\n» ;
>
class TestCase
public $a = 1 ;
protected $b = 2 ;
private $c = 3 ;
public static function expose ()
echo format ( get_class_vars ( __CLASS__ ));
>
>
TestCase :: expose ();
echo format ( get_class_vars ( ‘TestCase’ ));
?>
The above example will output:
// 5.0.0 a| * b| TestCase c a| * b| TestCase c // 5.0.1 - 5.0.2 a|b|c a|b|c // 5.0.3 + a|b|c a
See Also
User Contributed Notes 15 notes
If you want to retrieve the class vars from within the class itself, use $this.
var $a ;
var $b ;
var $c ;
var $d ;
var $e ;
function GetClassVars ()
return array_keys ( get_class_vars ( get_class ( $this ))); // $this
>
$class_vars = $Foo -> GetClassVars ();
foreach ( $class_vars as $cvar )
echo $cvar . «
\n» ;
>
?>
Produces, after PHP 4.2.0, the following:
All 3 of get_object_vars, get_class_vars and reflection getDefaultProperties will reveal the name of the array. For serialization I recommend:
$cName = get_class ( $this );
$varTemplate = get_class_vars ( $cName )
foreach ( $varTemplate as $name => $defaultVal ) <
$vars [ $name ] = $this -> $name ; // gets actual val.
>
?>
No scan the $vars and create serialization string how you wish.
This protects against erroneous prior deserializing in maintaining the integrity of the class template and ignoring unintended object properties.
I needed to get only the class static variables, leaving out instance variables.
function get_static_vars ( $class ) $result = array();
foreach ( get_class_vars ( $class ) as $name => $default )
if (isset( $class ::$ $name ))
$result [ $name ] = $default ;
return $result ;
>
?>
That function returns only the public ones. The same pattern can be used inside a class, then it returns private and protected static variables, too:
static protected function get_static_vars ( $class = NULL ) if (!isset( $class )) $class = get_called_class ();
$result = array();
foreach ( get_class_vars ( $class ) as $name => $default )
if (isset( $class ::$ $name ))
$result [ $name ] = $default ;
return $result ;
>
?>
So I wanted to get a list of the public parameters in a child class using a static function pre-5.3.0 (< 5.3.0). In 5.3.0+ you would use the new 'static' like you would 'self' to get the late binding.
class childClass extends parentClass
public $id ;
public $name ;
public static function getFields ()
return self :: _getFields ( __CLASS__ );
>
>
abstract class parentClass
public $idInParent ;
public $nameInParent ;
abstract public static function getFields ();
final protected static function _getFields ( $className )
$rtn = array();
foreach ( array_keys ( get_class_vars ( $className )) as $var ) $rtn [] = $var ;
>
return $rtn ;
>
var_dump ( childClass :: getFields ());
?>
Results:
array(4) [0]=>
string(2) «id»
[1]=>
string(4) «name»
[2]=>
string(10) «idInParent»
[3]=>
string(12) «nameInParent»
>
There seems to be be a function to get constants missing , i.e. get_class_constants() . so here is a simple function for you all. Hopefully Zend will include this in the next round as a native php call, without using reflection.
function GetClassConstants ( $sClassName ) $oClass = new ReflectionClass ( $sClassName );
return $oClass -> getConstants ());
>
?>
If you need get the child protected/private vars ignoring the parent vars, use like this:
class childClass extends parentClass private $login ;
private $password ;
public function __set ( $key , $val ) if ( $key == ‘password’ )
$this -> $key = md5 ( $val );
else
$this -> $key = $val ;
>
>
class parentClass public $name ;
public $email ;
function __construct () $reflection = new ReflectionClass ( $this );
$vars = array_keys ( $reflection -> getdefaultProperties ());
$reflection = new ReflectionClass ( __CLASS__ );
$parent_vars = array_keys ( $reflection -> getdefaultProperties ());
$my_child_vars = array();
foreach ( $vars as $key ) if (! in_array ( $key , $parent_vars )) $my_child_vars [] = $key ;
>
>
$child_class = new childClass ();
?>
If you assign a constant value using the self-scope by default to a variable, get_class_vars() will result in a FATAL error.
class Foo const Bar = «error» ;
print_r ( get_class_vars ( «Foo» ));
?>
. but using «Foo::Bar» instead «self::Bar» will work 😉
class someClass public function toArray () $records = array();
foreach( $this as $key => $value ) $records [ $key ] = $value ;
>
in PHP5 to get all the vars (including private etc.) use:
$reflection = new ReflectionClass($class);
$defaults = $reflection->getdefaultProperties();
I propse following for getting Public members, always:
if (! function_exists ( «get_public_class_vars» )) function get_public_class_vars ( $class ) return get_class_vars ( $class );
>
>
if (! function_exists ( «get_public_object_vars» )) function get_public_object_vars ( $object ) return get_object_vars ( $object );
>
>
?>
This is to mitigate the problem and a feature that get_object_vars($this) returns private members. Running it simply outside the scope will get the public.
Iterating public members only and their defaults are enormously useful in e.g. in serialization classes such as options where each public member is an serializable that is saved and loaded.
Contrary to multiple comments throughout the manual, get_class_vars() performed within a class can access any public, protected, and private members.
class Foo public $x ;
protected $y ;
private $z ;
public function __sleep () return( get_class_vars ( __CLASS__ ) );
>
>
?>
works fine (returns x, y, & z). However, given the same class as above,
print_r ( get_class_vars ( «Foo» ) );
?>
will NOT return x, y, & z. Instead it will only return the public members (in our case, z).
This is one of the best php functions. Look at what you can do
class Object
var $updtFields;//keep track of affected values
function Object($record=»») if (is_array($record))
$this->updtFields = array();
foreach(array_keys(get_class_vars(get_class($this))) as $k)
if (isset($record[$k]))
$this->$k = $record[$k];
$this->updtFields[] = $k;
>
>
>//end of arrayToObject
function toDebug($nl=’
‘)
foreach(array_keys(get_class_vars(get_class($this))) as $k)
echo «$k = [» . $this->$k . «]»;
>//end of toDebug
>
and you define your class like this
class Person extends Object var $name; //same same as in the form
var $phone;
>
when you submmit the form, you can get the data like
//everything in just one line,cool!! Also if you use pear db or adodb when you get data from the database you can do the same thing except use the $row that you get from the database. Remember to ask the result is associative mode.
This is my core Object for everthing I do and it works great.
get_class_vars_assoc()
— Returns an associative array with name of (parent) class(es) as key(s) and corresponding class vars as sub-arrays. My boilerplate for some crude O/R mapping.
Note: vars re-defined in sub-classes are ignored.
class GrandClass public $grandVar ;
public $in_grand_and_parent ;
public $in_grand_and_child ;
public static function load () print_r ( self :: get_class_vars_assoc ());
>
protected static function get_class_vars_assoc () $called = get_called_class ();
//echo «called: $called \n»;
$classVars [ $called ] = array_keys ( get_class_vars ( $called ));
$parent = get_parent_class ( $called );
while ( $parent !== FALSE ) //echo «parent: $parent \n»;
$classVars [ $parent ] = array_keys ( get_class_vars ( $parent ));
$classVars [ $called ] = array_diff ( $classVars [ $called ],
$classVars [ $parent ]);
if ( isset( $prevParentVars ) ) $prevParentVars = array_diff ( $prevParentVars ,
$classVars [ $parent ]);
>
$prevParentVars = & $classVars [ $parent ];
$parent = get_parent_class ( $parent );
>
class ParentClass extends GrandClass public $in_grand_and_parent ;
public $parentVar ;
public $in_parent_and_child ;
>
class ChildClass extends ParentClass public $in_grand_and_child ;
public $in_parent_and_child ;
public $childVar ;
>
(
[1] => parentVar
[2] => in_parent_and_child
) [GrandClass] => Array
(
[0] => grandVar
[1] => in_grand_and_parent
[2] => in_grand_and_child
)
get_class_vars
Возвращает объявленные по умолчанию свойства указанного класса.
Список параметров
Возвращаемые значения
Возвращает ассоциативный массив объявленных свойств класса, видимых из текущей области видимости, с их значением по умолчанию. Получившиеся элементы массива имеют форму varname => value. В случае ошибки возвращается FALSE .
Список изменений
| Версия | Описание |
|---|---|
| 5.0.3 | В зависимости от области видимости, get_class_vars() вернет только те свойства, доступ к которым может быть получен из текущей области видимости. |
| 5.0.2 | Вызов get_class_vars() не вернет все свойства в качестве массива, в отличие от предыдущего поведения, где protected и private свойства имели префикс с нулевым байтом. |
| 5.0.1 | Вызов get_class_vars() покажет все свойства, как при конвертировании объекта в класс. |
Примеры
Пример #1 Пример использования get_class_vars()
var $var1 ; // переменная не имеет начального значения.
var $var2 = «xyz» ;
var $var3 = 100 ;
private $var4 ; // PHP 5
// конструктор
function myclass () // change some properties
$this -> var1 = «foo» ;
$this -> var2 = «bar» ;
return true ;
>
$class_vars = get_class_vars ( get_class ( $my_class ));
foreach ( $class_vars as $name => $value ) echo » $name : $value \n» ;
>
Результат выполнения данного примера:
// До PHP 4.2.0 var2 : xyz var3 : 100 // Начиная с PHP 4.2.0 var1 : var2 : xyz var3 : 100
Пример #2 get_class_vars() и поведение области видимости
function format ( $array )
return implode ( ‘|’ , array_keys ( $array )) . «\r\n» ;
>
class TestCase
public $a = 1 ;
protected $b = 2 ;
private $c = 3 ;
public static function expose ()
echo format ( get_class_vars ( __CLASS__ ));
>
>
TestCase :: expose ();
echo format ( get_class_vars ( ‘TestCase’ ));
?>
Результат выполнения данного примера:
// 5.0.0 a| * b| TestCase c a| * b| TestCase c // 5.0.1 - 5.0.2 a|b|c a|b|c // 5.0.3 + a|b|c a