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get_class_vars — 返回由类的默认属性组成的数组

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get_class_vars

(PHP 4, PHP 5)

get_class_vars — 返回由类的默认属性组成的数组

说明 ¶

array get_class_vars ( string $class_name )

返回由类的默认公有属性组成的关联数组,此数组的元素以 varname => value 的形式存在。

Note:

在 PHP 4.2.0 之前,get_class_vars() 不会包含未初始化的类变量。

Example #1 get_class_vars() 示例

<?php

class myclass {

    var 
$var1// 此变量没有默认值……
    
var $var2 "xyz";
    var 
$var3 100;
    private 
$var4// PHP 5

    // constructor
    
function myclass() {
        
// change some properties
        
$this->var1 "foo";
        
$this->var2 "bar";
        return 
true;
    }

}


$my_class = new myclass();

$class_vars get_class_vars(get_class($my_class));

foreach (
$class_vars as $name => $value) {
    echo 
"$name : $value\n";
}


?>

以上例程会输出:

// 在 PHP 4.2.0 之前
var2 : xyz
var3 : 100

// 从 PHP 4.2.0 开始
var1 :
var2 : xyz
var3 : 100

参见 get_class_methods()、 get_object_vars()

参数 ¶

class_name

The class name

返回值 ¶

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.

更新日志 ¶

版本说明
5.0.3Depending on the scope, get_class_vars() will only return the properties that can be accessed from the current scope.
5.0.2Calling get_class_vars() will now expose all the properties as an array, unlike previous behaviour where protected and private properties were prefixed with nul bytes.
5.0.1Calling get_class_vars() will expose all properties, as when converting an object to a class.
Prior to 4.2.0Uninitialized class variables will not be reported by get_class_vars()

范例 ¶

Example #2 get_class_vars() example

<?php

class myclass {

    var 
$var1// this has no default value...
    
var $var2 "xyz";
    var 
$var3 100;
    private 
$var4// PHP 5

    // constructor
    
function myclass() {
        
// change some properties
        
$this->var1 "foo";
        
$this->var2 "bar";
        return 
true;
    }

}


$my_class = new myclass();

$class_vars get_class_vars(get_class($my_class));

foreach (
$class_vars as $name => $value) {
    echo 
"$name : $value\n";
}


?>

以上例程会输出:

// Before PHP 4.2.0
var2 : xyz
var3 : 100

// As of PHP 4.2.0
var1 :
var2 : xyz
var3 : 100

Example #3 get_class_vars() and scoping behaviour

<?php
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'));
?>

以上例程会输出:

// 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

参见 ¶

add a note add a note

User Contributed Notes 14 notes

rec at NOSPAM dot instantmassacre dot com ¶
12 years ago
If you want to retrieve the class vars from within the class itself, use $this.

<?php
class Foo {

    var 
$a;
    var 
$b;
    var 
$c;
    var 
$d;
    var 
$e;

    function 
GetClassVars()
    {
        return 
array_keys(get_class_vars(get_class($this))); // $this
    
}

}


$Foo = new Foo;

$class_vars $Foo->GetClassVars();

foreach (
$class_vars as $cvar)
{
    echo 
$cvar "<br />\n";
}

?>

Produces, after PHP 4.2.0, the following:

a
b
c
d
e
bof at bof dot de ¶
2 years ago
I needed to get only the class static variables, leaving out instance variables.

<?php
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:

<?php
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;
}

?>
ken at verango dot com ¶
4 years ago
All 3 of get_object_vars, get_class_vars and reflection getDefaultProperties will reveal the name of the array.  For serialization I recommend: 

<?php 
$cName 
get_class($this); 
$varTemplateget_class_vars($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.
ianitsky at gmail dot com ¶
5 years ago
If you need get the child protected/private vars ignoring the parent vars, use like this:

<?php 
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;
            }
        }
        
        
print_r($my_child_vars);
    }
}


$child_class = new childClass();
?>
alan_k at php dot net ¶
10 years ago
in PHP5 to get all the vars (including private etc.) use:

$reflection = new ReflectionClass($class);
$defaults = $reflection->getdefaultProperties();
ciantic ¶
3 years ago
I propse following for getting Public members, always:
<?PHP
if (!function_exists("get_public_class_vars")) {
    function 
get_public_class_vars($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.
harmor ¶
6 years ago
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.

<?php
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"
}
artktec at art-k-tec dot com ¶
7 years ago
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.

<?php
   
function GetClassConstants($sClassName) {
      
$oClass = new ReflectionClass($sClassName);
      return 
$oClass->getConstants());
   }

?>
php dot net at sharpdreams dot com ¶
9 years ago
Contrary to multiple comments throughout the manual, get_class_vars() performed within a class can access any public, protected, and private members.

<?php
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,

<?php
print_r
get_class_vars"Foo" ) );
?>

will NOT return x, y, & z. Instead it will only return the public members (in our case, z).
bernd at tiggerswelt dot net ¶
8 years ago
If you assign a constant value using the self-scope by default to a variable, get_class_vars() will result in a FATAL error.

Example:

<?PHP

  
class Foo {
    const 
Bar "error";
    
    public 
$Foo self::Bar;
  }
  
  
print_r(get_class_vars("Foo"));

?>

... but using "Foo::Bar" instead "self::Bar" will work ;)
pBakhuis at Gmail dot com ¶
3 years ago
If you need the variables before the class is included this function does not seem to work. 
Use a reflection class to get around this. 
http://www.php.net/reflectionclass
phpnet at stccorp dot net ¶
8 years ago
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($nl='<br>')
   {
       foreach(array_keys(get_class_vars(get_class($this))) as $k)
       echo "$k = [" . $this->$k . "]{$nl}";
    }//end of toDebug  
}

Now you can do really cool things. If you have a form like 
<form action="" method="post">
  <input type="text" name="name" />
  <input type="text" name="phone" />
  <input type="submit" />
</form>

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

$person = new Person($_POST);

//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.
Mattias Ahlbck ¶
3 years ago
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.

<?php

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);
        }
        
        return 
$classVars;
    }
}

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;
}


ChildClass::load();

?>

Array
(
    [ChildClass] => Array
        (
            [2] => childVar
        )

    [ParentClass] => Array
        (
            [1] => parentVar
            [2] => in_parent_and_child
        )

    [GrandClass] => Array
        (
            [0] => grandVar
            [1] => in_grand_and_parent
            [2] => in_grand_and_child
        )

)
gizmobits at hotmail dot com ¶
9 years ago
I wanted a simple ToString() function that was automatic and class independent.  I wanted to dump it into any of several classes and get values quickly.  I wanted to leave it there so I could customize it for each class, so an outside function wasn't suitable.  I came up with this and thought it might be useful.  Have fun!

<?php
  
function ToString () {
    
$s "";
    
$s .= "<table>\n";
    
$s .= "<tr><td colspan=2><hr></td></tr>\n";
    foreach (
get_class_vars(get_class($this)) as $name => $value) {
      
$s .= "<tr><td>$name:</td><td>" $this->$name "</td></tr>\n";
    }
    
$s .= "<tr><td colspan=2><hr></td></tr>\n";
    
$s .= "</table>\n";
    return 
$s;
  }


?>
来自  http://php.net/manual/zh/function.get-class-vars.php
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