(PHP 8)
ReflectionProperty::getDefaultValue — Returns the default value declared for a property
Gets the implicit or explicitly declared default value for a property.
此函数没有参数。
The default value if the property has any default value (including null).
If there is no default value, then null is returned. It is not possible to differentiate
between a null default value and an unitialized typed property.
Use ReflectionProperty::hasDefaultValue() to detect the difference.
示例 #1 ReflectionProperty::getDefaultValue() example
<?php
class Foo {
public $bar = 1;
public ?int $baz;
public int $boing = 0;
public function __construct(public string $bak = "default") { }
}
$ro = new ReflectionClass(Foo::class);
var_dump($ro->getProperty('bar')->getDefaultValue());
var_dump($ro->getProperty('baz')->getDefaultValue());
var_dump($ro->getProperty('boing')->getDefaultValue());
var_dump($ro->getProperty('bak')->getDefaultValue());
?>以上示例会输出：
int(1) NULL int(0) NULL
An equivalent for PHP 7:
<?php
$reflectionProperty = new \ReflectionProperty(Foo::class, 'bar');
//PHP 8:
$defaultValue = $reflectionProperty->getDefaultValue();
//PHP 7:
$defaultValue = $reflectionProperty->getDeclaringClass()->getDefaultProperties()['bar'] ?? null;
?>