(PHP 8)
ReflectionProperty::hasDefaultValue — Checks if property has a default value declared
Checks whether the property was declared with a default value, including an implicit
null default value. Only returns false for typed properties without default value (or
dynamic properties).
This function has no parameters.
If the property has any default value (including null) true is returned;
if the property is typed without a default value declared or is a dynamic property, false is returned.
Example #1 ReflectionProperty::hasDefaultValue() example
<?php
class Foo {
public $bar;
public ?int $baz;
public ?int $foo = null;
public int $boing;
public function __construct()
{
$this->ping = '';
}
}
$ro = new ReflectionObject(new Foo());
var_dump($ro->getProperty('bar')->hasDefaultValue());
var_dump($ro->getProperty('baz')->hasDefaultValue());
var_dump($ro->getProperty('foo')->hasDefaultValue());
var_dump($ro->getProperty('boing')->hasDefaultValue());
var_dump($ro->getProperty('ping')->hasDefaultValue()); // Dynamic property
var_dump($ro->getProperty('pong')->hasDefaultValue()); // Not defined property
?>The above example will output:
bool(true) bool(false) bool(true) bool(false) bool(false) Fatal error: Uncaught ReflectionException: Property Foo::$pong does not exist in example.php
It is useful to note that if this is used on a promoted property, which has a default value, it does not work as expected. The default value is related to the constructor parameter, not to the property itself. So for example, if you reflect this property:
<?php
class SomeClass
{
public function __construct(
public ?string $property = null,
) {
}
}
?>
The ReflectionProperty::hasDefaultValue will return false.