ReflectionProperty::setValue

(PHP 5, PHP 7, PHP 8)

ReflectionProperty::setValue — Set property value

说明

public ReflectionProperty::setValue(?object $object, mixed $value): void

public ReflectionProperty::setValue(mixed $value): void

Sets (changes) the property's value.

注意: To set static property values, use ReflectionProperty::setValue(null, $value).

参数

object: For static properties, pass in null. For non-static properties, pass in the object.
value: The new value.

返回值

没有返回值。

更新日志

版本	说明
8.3.0	Calling this method with a single argument is deprecated, instead use `ReflectionProperty::setValue(null, $value)` for 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.

示例

示例 #1 ReflectionProperty::setValue() example

<?php
class Foo {
    public static $staticProperty;
    
    public $property;
    protected $privateProperty;
}

$reflectionClass = new ReflectionClass('Foo');

// As of PHP 8.3, passing in null as the first argument is required
// to access static properties.
$reflectionProperty = $reflectionClass->getProperty('staticProperty');
$reflectionProperty->setValue(null, 'foo');
var_dump(Foo::$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));
?>

以上示例会输出：

string(3) "foo"
string(3) "bar"
string(6) "foobar"

参见

ReflectionProperty::getValue() - Gets value
ReflectionProperty::setAccessible() - Set property accessibility
ReflectionClass::setStaticPropertyValue() - 设置静态属性的值

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用户贡献的备注 3 notes

down

me at ircmaxell dot om ¶

13 years ago

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"
?>

down

p stewart imperial ac uk ¶

2 years ago

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.

down

temirkhan.nasukhov ¶

2 years ago

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