Below three examples describe anonymous class with very simple and basic but quite understandable example
<?php
// First way - anonymous class assigned directly to variable
$ano_class_obj = new class{
public $prop1 = 'hello';
public $prop2 = 754;
const SETT = 'some config';
public function getValue()
{
// do some operation
return 'some returned value';
}
public function getValueWithArgu($str)
{
// do some operation
return 'returned value is '.$str;
}
};
echo "\n";
var_dump($ano_class_obj);
echo "\n";
echo $ano_class_obj->prop1;
echo "\n";
echo $ano_class_obj->prop2;
echo "\n";
echo $ano_class_obj::SETT;
echo "\n";
echo $ano_class_obj->getValue();
echo "\n";
echo $ano_class_obj->getValueWithArgu('OOP');
echo "\n";
echo "\n";
// Second way - anonymous class assigned to variable via defined function
$ano_class_obj_with_func = ano_func();
function ano_func()
{
return new class {
public $prop1 = 'hello';
public $prop2 = 754;
const SETT = 'some config';
public function getValue()
{
// do some operation
return 'some returned value';
}
public function getValueWithArgu($str)
{
// do some operation
return 'returned value is '.$str;
}
};
}
echo "\n";
var_dump($ano_class_obj_with_func);
echo "\n";
echo $ano_class_obj_with_func->prop1;
echo "\n";
echo $ano_class_obj_with_func->prop2;
echo "\n";
echo $ano_class_obj_with_func::SETT;
echo "\n";
echo $ano_class_obj_with_func->getValue();
echo "\n";
echo $ano_class_obj_with_func->getValueWithArgu('OOP');
echo "\n";
echo "\n";
// Third way - passing argument to anonymous class via constructors
$arg = 1; // we got it by some operation
$config = [2, false]; // we got it by some operation
$ano_class_obj_with_arg = ano_func_with_arg($arg, $config);
function ano_func_with_arg($arg, $config)
{
return new class($arg, $config) {
public $prop1 = 'hello';
public $prop2 = 754;
public $prop3, $config;
const SETT = 'some config';
public function __construct($arg, $config)
{
$this->prop3 = $arg;
$this->config =$config;
}
public function getValue()
{
// do some operation
return 'some returned value';
}
public function getValueWithArgu($str)
{
// do some operation
return 'returned value is '.$str;
}
};
}
echo "\n";
var_dump($ano_class_obj_with_arg);
echo "\n";
echo $ano_class_obj_with_arg->prop1;
echo "\n";
echo $ano_class_obj_with_arg->prop2;
echo "\n";
echo $ano_class_obj_with_arg::SETT;
echo "\n";
echo $ano_class_obj_with_arg->getValue();
echo "\n";
echo $ano_class_obj_with_arg->getValueWithArgu('OOP');
echo "\n";
echo "\n";
Anonyme Klassen
Anonyme Klassen sind nützlich, wenn einfache Objekte zum einmaligen Gebrauch erzeugt werden müssen.
<?php
// Verwendung einer expliziten Klasse
class Logger
{
public function log($msg)
{
echo $msg;
}
}
$util->setLogger(new Logger());
// Verwendung einer anonymen Klasse
$util->setLogger(new class {
public function log($msg)
{
echo $msg;
}
});Anonyme Klassen können Argumente über ihren Konstruktor empfangen, andere Klassen erweitern, Interfaces implementieren und Traits genau wie eine normale Klasse verwenden:
<?php
class SomeClass {}
interface SomeInterface {}
trait SomeTrait {}
var_dump(new class(10) extends SomeClass implements SomeInterface {
private $num;
public function __construct($num)
{
$this->num = $num;
}
use SomeTrait;
});Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
object(class@anonymous)#1 (1) {
["Command line code0x104c5b612":"class@anonymous":private]=>
int(10)
}
Das Verschachteln einer anonymen Klasse innerhalb einer anderen Klasse gibt ihr keinen Zugriff auf private oder geschützte Methoden oder Eigenschaften der äußeren Klasse. Um die geschützten Methoden oder Eigenschaften der äußeren Klasse zu verwenden, kann die anonyme Klasse die äußere Klasse erweitern. Um private Eigenschaften der äußeren Klasse in der anonymen Klasse zu verwenden, müssen sie dem Konstruktor übergeben werden:
<?php
class Outer
{
private $prop = 1;
protected $prop2 = 2;
protected function func1()
{
return 3;
}
public function func2()
{
return new class($this->prop) extends Outer {
private $prop3;
public function __construct($prop)
{
$this->prop3 = $prop;
}
public function func3()
{
return $this->prop2 + $this->prop3 + $this->func1();
}
};
}
}
echo (new Outer)->func2()->func3();Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
6
Alle Objekte, die durch dieselbe anonyme Klassendeklaration erzeugt werden, sind Instanzen von genau dieser Klasse.
<?php
function anonymous_class()
{
return new class {};
}
if (get_class(anonymous_class()) === get_class(anonymous_class())) {
echo 'dieselbe Klasse';
} else {
echo 'eine andere Klasse';
}Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
dieselbe Klasse
Hinweis:
Es ist zu beachten, dass anonymen Klassen von der Engine ein Name zugewiesen wird, wie im folgenden Beispiel gezeigt. Dieser Name muss als Implementierungsdetail eingestuft werden, auf dass sich nicht verlassen werden sollte.
<?php
echo get_class(new class {});Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
class@anonymous/in/oNi1A0x7f8636ad2021
add a note
User Contributed Notes 9 notes
Anonymous ¶
8 years ago
ytubeshareit at gmail dot com ¶
7 years ago
Anonymous classes are syntax sugar that may appear deceiving to some.
The 'anonymous' class is still parsed into the global scope, where it is auto assigned a name, and every time the class is needed, that global class definition is used. Example to illustrate....
The anonymous class version...
<?php
function return_anon(){
return new class{
public static $str="foo";
};
}
$test=return_anon();
echo $test::$str; //ouputs foo
//we can still access the 'anon' class directly in the global scope!
$another=get_class($test); //get the auto assigned name
echo $another::$str; //outputs foo
?>
The above is functionally the same as doing this....
<?php
class I_named_this_one{
public static $str="foo";
}
function return_not_anon(){
return 'I_named_this_one';
}
$clzz=return_not_anon();//get class name
echo $clzz::$str;
?>
joey ¶
5 years ago
The only way to type hint this would appear to be as object.
If you need multiple instances of an anonymous class in a function you can use:
$class = function(string $arg):object {
return new class($arg) {
public function __construct(string $arg) {
$this->ow = $arg;
}
};
};
Though for the sake of structure it's ill advised to do something like this outside of a single scope or that's used across multiple files. If you class is only used in one scope however then it's probably not a code mess problem.
sebastian.wasser at gmail ¶
5 years ago
I wanted to share my findings on static properties of anonymous classes.
So, given an anonymous class' object generating function like this:
<?php
function nc () {
return new class {
public static $prop = [];
};
}
?>
Getting a new object and changing the static property:
<?php
$a = nc();
$a::$prop[] = 'a';
var_dump($a::$prop);
// array(1) {
// [0] =>
// string(1) "a"
// }
?>
Now getting another object and changing the static property will change the original one, meaning that the static property is truly static:
<?php
$b = nc();
$b::$prop[] = 'b';
var_dump($b::$prop); // Same as var_dump($a::$prop);
// array(2) {
// [0] =>
// string(1) "a"
// [1] =>
// string(1) "b"
// }
assert($a::$prop === $b::$prop); // true
?>
razvan_bc at yahoo dot com ¶
4 years ago
you can try these
<?php
$oracle=&$_['nice_php'];
$_['nice_php']=(function(){
return new class{
public static function say($msg){
echo $msg;
}
public static function sp(){
echo self::say(' ');
}
};
});
/*
$_['nice_php']()::say('Hello');
$_['nice_php']()::sp();
$_['nice_php']()::say('World');
$_['nice_php']()::sp();
$_['nice_php']()::say('!');
//almost the same code bottom
*/
$oracle()::say('Hello');
$oracle()::sp();
$oracle()::say('World');
$oracle()::sp();
$oracle()::say('!');
?>
j.m \ jamesweb \ ca ¶
7 years ago
/* I like the idea of OneShot classes.
Thanks to that Anonymous bro\sist for precising
new class( $a, $b )
¯¯¯¯¯¯¯¯¯
If you are looking for "Delayed OneShot Anonymous Classes" for any reason (like the reason: loading files in a readable manner while not using autoload), it would probably look something like this; */
$u = function()use(&$u){
$u = new class{private $name = 'Utils';};
};
$w = function(&$rewrite)use(&$w){
$w = null;
$rewrite = new class{private $name = 'DataUtils';};
};
// Usage;
var_dump(
array(
'Delayed',
'( Self Destructive )',
'Anonymous Class Creation',
array(
'Before ( $u )' => $u,
'Running ( $u() )' => $u(),
'After ( $u )' => $u,
),
0,0,
0,0,
0,0,
'Delayed',
'( Overwriting && Self Destructive )',
'Anonymous Class Creation',
array(
'Before ( $w )' => $w,
'Running ( $w($u) )' => $w($u),
'After ( $w )' => $w,
'After ( $u )' => $u
)
)
);
// btw : oh shoot I failed a spam challenge
piotr at maslosoft dot com ¶
7 years ago
Please note that class name returned by `get_class` might contain null bytes, as is the case in my version of PHP (7.1.4).
Name will change when class starting line or it's body is changed.
Yes, name is implementation detail that should not be relied upon, but in some rare use cases it is required (annotating anonymous class).
solobot ¶
7 years ago
eval() is workaround for generating multiple anonymous classes with static properties in loop
<?php
public function generateClassMap()
{
foreach ($this->classMap as $tableName => $class)
{
$c = null;
eval('$c = new class extends \common\MyStaticClass {
public static $tableName;
public static function tableName()
{
return static::$tableName;
}
};');
$c::$tableName = $this->replicationPrefix.$tableName;
$this->classMap[$tableName] = $c;
}
}
?>
thus every class will have its own $tableName instead of common ancestor.
primipilus13 at gmail dot com ¶
8 years ago
<?php
// using constructor and extends in anonymous class
class A
{
private $name;
public function __construct($name)
{
$this->name = $name;
}
public function getName()
{
return $this->name;
}
}
$b = new class('anonymous') extends A
{
public function getName()
{
return parent::getName() . ' class';
}
};
echo $b->getName(), PHP_EOL;
// result: anonimous class
