Anonymous (class)es
Support for anonymous classes was added in PHP 7. Anonymous classes are useful when simple, one-off objects need to be created.
<?php
//?Pre?PHP?7?code
class?Logger
{
????public?function?log($msg)
????{
????????echo?$msg;
????}
}
$util->setLogger(new?Logger());
//?PHP?7+?code
$util->setLogger(new?class?{
????public?function?log($msg)
????{
????????echo?$msg;
????}
});They can pass arguments through to their constructors, extend other classes, implement interfaces, and use traits just like a normal class can:
<?php
class?SomeClass?{}
interface?SomeInterface?{}
trait?SomeTrait?{}
var_dump(new?class(10)?extends?SomeClass?implements?SomeInterface?{
????private?$num;
????public?function?__construct($num)
????{
????????$this->num?=?$num;
????}
????use?SomeTrait;
});The above example will output:
object(class@anonymous)#1 (1) {
["Command line code0x104c5b612":"class@anonymous":private]=>
int(10)
}Nesting an anonymous class within another class does not give it access to any private or protected methods or properties of that outer class. In order to use the outer class' protected properties or methods, the anonymous class can extend the outer class. To use the private properties of the outer class in the anonymous class, they must be passed through its constructor:
<?php
class?Outer
{
????private?$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();The above example will output:
6All objects created by the same anonymous class declaration are instances of that very class.
<?php
function?anonymous_class()
{
????return?new?class?{};
}
if?(get_class(anonymous_class())?===?get_class(anonymous_class()))?{
????echo?'same?class';
}?else?{
????echo?'different?class';
}The above example will output:
same classNote: Note that anonymous classes are assigned a name by the engine, as demonstrated in the following example. This name has to be regarded an implementation detail, which should not be relied upon. <?php echo?get\_class(new?class?{}); The above example will output something similar to: class@anonymous/in/oNi1A0x7f8636ad2021
← Traits
Overloading →
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