(PHP 5, PHP 7, PHP 8)
ReflectionProperty::setValue — Set property value
Sets (changes) the property's value.
Note: As of PHP 8.3.0, calling this method with a single argument is deprecated, use ReflectionClass::setStaticPropertyValue() instead.
object
If the property is non-static an object must be provided to change
the property on.
If the property is static a value of null must be to be provided.
valueThe new value.
No value is returned.
| Version | Description |
|---|---|
| 8.3.0 | Calling this method with a single argument is deprecated, ReflectionClass::setStaticPropertyValue() should be used instead to modify static properties. |
| 8.1.0 | Private and protected properties can be accessed by ReflectionProperty::setValue() right away. Previously, they needed to be made accessible by calling ReflectionProperty::setAccessible(); otherwise a ReflectionException was thrown. |
Example #1 ReflectionProperty::setValue() example
<?php
class Foo {
public static $staticProperty;
public $property;
protected $privateProperty;
}
$reflectionClass = new ReflectionClass('Foo');
// As of PHP 8.3, setValue should no longer be used to set static property value, use setStaticPropertyValue() instead
$reflectionClass->setStaticPropertyValue('staticProperty', 'foo');
var_dump(Foo::$staticProperty);
$foo = new Foo;
$reflectionClass->getProperty('property')->setValue($foo, 'bar');
var_dump($foo->property);
$reflectionProperty = $reflectionClass->getProperty('privateProperty');
$reflectionProperty->setAccessible(true); // only required prior to PHP 8.1.0
$reflectionProperty->setValue($foo, 'foobar');
var_dump($reflectionProperty->getValue($foo));
?>The above example will output:
string(3) "foo" string(3) "bar" string(6) "foobar"
You can use ReflectionProperty::setValue to set the value on static properties as well as regular instance properties. Simply pass null in place of the instance:
<?php
class Foo {
protected static $bar = null;
public static function sayBar() {
echo self::$bar;
}
}
$r = new ReflectionProperty('Foo', 'bar');
$r->setAccessible(true);
$r->setValue(null, 'foo');
Foo::sayBar(); // "foo"
?>setValue can be used for readonly properties, but only if the property has not yet been initialised:
<?php
class Person
{
private readonly int $age;
public function __construct(array $props = []) {
if (isset($props['age'])) {
$this->age = (int)$props['age'];
}
}
}
$personWithKnownAge = new Person(['age' => 50]);
$reflection = new ReflectionProperty($personWithKnownAge, 'age');
$reflection->setValue($personWithKnownAge, 10); // Fails - Age is already initialised, value cannot be changed.
$personWithUnknownAge = new Person();
$reflection = new ReflectionProperty($personWithUnknownAge, 'age');
$reflection->setValue($personWithUnknownAge, 10); // Succeeeds - Age is not yet initialised, value can be set.
?>
This can be useful for situations where it is desirable to initialise properties from outside of the defining class, for example an ORM setup where the parent class is responsible for setting properties on a model subclass instance.Keep in mind that setValue won't work for readonly properties.
<?php
class Person
{
public function __construct(private readonly int $age) {}
}
$someOldPerson = new Person(80);
$reflection = new ReflectionProperty($someOldPerson, 'age');
$reflection->setValue($someOldPerson, 10); // Fatal error: Uncaught Error: Cannot modify readonly property Person::$age