How do you get value from private properties in PHP [duplicate] - php

Question

It doesn't seem to work:
$ref = new ReflectionObject($obj);
if($ref->hasProperty('privateProperty')){
print_r($ref->getProperty('privateProperty'));
}
It gets into the IF loop, and then throws an error:
Property privateProperty does not exist
:|
$ref = new ReflectionProperty($obj, 'privateProperty') doesn't work either...
The documentation page lists a few constants, including IS_PRIVATE. How can I ever use that if I can't access a private property lol?

Answer 1

class A
{
private $b = 'c';
}
$obj = new A();
$r = new ReflectionObject($obj);
$p = $r->getProperty('b');
$p->setAccessible(true); // <--- you set the property to public before you read the value
var_dump($p->getValue($obj));

Answer 2

Please, note that accepted answer will not work if you need to get the value of a private property which comes from a parent class.
For this you can rely on getParentClass method of Reflection API.
Also, this is already solved in this micro-library.
More details in this blog post.

Answer 3

getProperty throws an exception, not an error. The significance is, you can handle it, and save yourself an if:
$ref = new ReflectionObject($obj);
$propName = "myProperty";
try {
$prop = $ref->getProperty($propName);
} catch (ReflectionException $ex) {
echo "property $propName does not exist";
//or echo the exception message: echo $ex->getMessage();
}
To get all private properties, use $ref->getProperties(ReflectionProperty::IS_PRIVATE);

Answer 4

In case you need it without reflection:
public function propertyReader(): Closure
{
return function &($object, $property) {
$value = &Closure::bind(function &() use ($property) {
return $this->$property;
}, $object, $object)->__invoke();
return $value;
};
}
and then just use it (in the same class) like this:
$object = new SomeObject();
$reader = $this->propertyReader();
$result = &$reader($object, 'some_property');

Answer 5

Without reflection, one can also do
class SomeHelperClass {
// Version 1
public static function getProperty1 (object $object, string $property) {
return Closure::bind(
function () use ($property) {
return $this->$property;
},
$object,
$object
)();
}
// Version 2
public static function getProperty2 (object $object, string $property) {
return (
function () use ($property) {
return $this->$property;
}
)->bindTo(
$object,
$object
)->__invoke();
}
}
and then something like
SomeHelperClass::getProperty1($object, $propertyName)
SomeHelperClass::getProperty2($object, $propertyName)
should work.
This is a simplified version of Nikola Stojiljković's answer