property_exists

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

property_exists — Checks if the object or class has a property

Description

function property_exists(object|string $object_or_class, string $property): bool

This function checks if the given property exists in the specified class.

Note:
As opposed to isset(), property_exists() returns true even if the property has the value null.

Parameters

object_or_class: The class name or an object of the class to test for
property: The name of the property

Return Values

Returns true if the property exists, false if it doesn't exist.

Examples

Example #1 A property_exists() example

<?php

class myClass {
    public $mine;
    private $xpto;
    static protected $test;

    static function test() {
        var_dump(property_exists('myClass', 'xpto')); //true
    }
}

var_dump(property_exists('myClass', 'mine'));   //true
var_dump(property_exists(new myClass, 'mine')); //true
var_dump(property_exists('myClass', 'xpto'));   //true
var_dump(property_exists('myClass', 'bar'));    //false
var_dump(property_exists('myClass', 'test'));   //true
myClass::test();

?>

property_exists() returns true regardless of property visibility, detects dynamic properties added to instances (when the class uses #[AllowDynamicProperties]), and ignores __isset and __get magic methods.

Example #2 Visibility, dynamic properties, and magic methods

<?php

#[AllowDynamicProperties]
class MyClass {
    public $public;
    private $private;
    static protected $protectedStatic;

    // ignored by property_exists
    public function __isset(string $name): bool {
        return true;
    }

    // ignored by property_exists
    public function __get(string $name): string {
        return '';
    }
}

$instance = new MyClass();
$instance->instanced = 'abc';

var_dump(property_exists($instance, 'public'));          // true  (public)
var_dump(property_exists($instance, 'private'));         // true  (visibility ignored)
var_dump(property_exists($instance, 'protectedStatic')); // true  (visibility ignored)
var_dump(property_exists($instance, 'instanced'));       // true  (dynamic property on instance)
var_dump(property_exists($instance, 'undefined'));       // false (not declared, __isset ignored)

var_dump(property_exists(MyClass::class, 'public'));    // true
var_dump(property_exists(MyClass::class, 'instanced')); // false (dynamic props not on class)
var_dump(property_exists(MyClass::class, 'undefined')); // false

?>

The above example will output:

bool(true)
bool(true)
bool(true)
bool(true)
bool(false)
bool(true)
bool(false)
bool(false)

Notes

Note:
Using this function will use any registered autoloaders if the class is not already known.