PHP 8.1.15 Released!

ReflectionProperty::setValue

(PHP 5, PHP 7, PHP 8)

ReflectionProperty::setValueSet property value

说明

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

Sets (changes) the property's value.

参数

object

If the property is non-static an object must be provided to change the property on. If the property is static this parameter is left out and only value needs to be provided.

value

The new value.

返回值

没有返回值。

更新日志

版本 说明
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.

范例

示例 #1 ReflectionProperty::setValue() example

<?php
class Foo {
public static
$staticProperty;

public
$property;
protected
$privateProperty;
}

$reflectionClass = new ReflectionClass('Foo');

$reflectionClass->getProperty('staticProperty')->setValue('foo');
var_dump(Foo::$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));
?>

以上例程会输出:

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

参见

add a note

User Contributed Notes 3 notes

up
1
me at ircmaxell dot om
11 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"
?>
up
1
p stewart imperial ac uk
1 month 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.
up
0
temirkhan.nasukhov
3 months 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
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