(PHP 5, PHP 7, PHP 8)
ReflectionClass::getConstants — 获取常量
$filter = null): array从类中获取所有已定义的常量，而不管它们的可见性如何。
filter可选过滤器，传入过滤所需的可见性常量。可用 ReflectionClassConstant 常量 进行配置，默认为所有可见性常量。
常量的数组，常量名是数组的键，常量的值是数组的值。
| 版本 | 说明 |
|---|---|
| 8.0.0 |
添加 filter 。
|
If you want to return the constants defined inside a class then you can also define an internal method as follows:
<?php
class myClass {
const NONE = 0;
const REQUEST = 100;
const AUTH = 101;
// others...
static function getConstants() {
$oClass = new ReflectionClass(__CLASS__);
return $oClass->getConstants();
}
}
?>You can pass $this as class for the ReflectionClass. __CLASS__ won't help if you extend the original class, because it is a magic constant based on the file itself.
<?php
class Example {
const TYPE_A = 1;
const TYPE_B = 'hello';
public function getConstants()
{
$reflectionClass = new ReflectionClass($this);
return $reflectionClass->getConstants();
}
}
$example = new Example();
var_dump($example->getConstants());
// Result:
array ( size = 2)
'TYPE_A' => int 1
'TYPE_B' => (string) 'hello'If you want to define a static getConstants() function which works with inheritance you can do the following:
<?php
abstract class AbstractClass
{
const TEST = "test";
public static function getConstants()
{
// "static::class" here does the magic
$reflectionClass = new ReflectionClass(static::class);
return $reflectionClass->getConstants();
}
}
class ChildClass extends AbstractClass
{
const TYPE_A = 1;
const TYPE_B = 'hello';
}
$example = new ChildClass();
var_dump($example->getConstants());
// Result:
array(3) {
'TYPE_A' => int(1)
'TYPE_B' => string(5) "hello"
'TEST' => string(4) "test"
}
?>I use a functions to do somthing base on the class constant name as below. This example maybe helpful for everybody.
<?php
public function renderData($question_type = NULL, $data = array()) {
$types = array();
$qt = new ReflectionClass(questionType);
$types = $qt->getConstants();
if ($type = array_search($question_type, $types)){
//.....Do somthing
}
}
?>I was trying to determine how to get a var_dump of constants that are within an interface. Thats right, not using any classes but the interface itself.
Along my travels I found it quite interesting that the ReflectionClass along with a direct call to the interface will also dump its constants. Perfect!!!!
This was using PHP 5.3.1 and my example as below:-
1st File:
constants.php
<?php
<?php>
interface MyConstants
{
// --------------------------
// Programmatic Level
// --------------------------
const DEBUG_MODE_ACTIVE = FALSE;
const PHP_VERSION_REQUIREMENT = "5.1.2";
}
?>
=======
Second file:
=======
test.php
<?php>
include_once ("constants.php");
$oClass = new ReflectionClass ('MyConstants');
$array = $oClass->getConstants ();
var_dump ($array);
unset ($oClass);
?>
what you would get from the command line:-
?:\???\htdocs\????>php test.php
array(2) {
["DEBUG_MODE_ACTIVE"]=> bool(false)
["PHP_VERSION_REQUIREMENT"]=> string(5) "5.1.2"
But as you can see this can work quite well to your advantage in many ways so I truely hope this helps someone else with a similar headache in the future to come!
Enjoy!Get the latest constants declared.
abstract class AbstractEnum
{
/**
* Возвращает все константы класса || Return all constants
*
* @return array
*/
static function getConstants()
{
$rc = new \ReflectionClass(get_called_class());
return $rc->getConstants();
}
/**
* Возвращает массив констант определенные в вызываемом классе || Return last constants
*
* @return array
*/
static function lastConstants()
{
$parentConstants = static::getParentConstants();
$allConstants = static::getConstants();
return array_diff($allConstants, $parentConstants);
}
/**
* Возвращает все константы родительских классов || Return parent constants
*
* @return array
*/
static function getParentConstants()
{
$rc = new \ReflectionClass(get_parent_class(static::class));
$consts = $rc->getConstants();
return $consts;
}
}
======
class Roles extends AbstractEnum
{
const ROOT = 'root';
const ADMIN = 'admin';
const USER = 'user';
}
// Output:
All: root, admin, user
Last: root, admin, user
class NewRoles extends Roles
{
const CLIENT = 'client';
const MODERATOR = 'moderator';
const SUPERMODERATOR = 'super'.self::USER;
}
// Output:
All: client, moderator, superuser, root, admin, user
Last: client, moderator, superuser
class AdditionalRoles extends Roles
{
const VIEWER = 'viewer';
const CHECKER = 'checker';
const ROOT = 'rooter';
}
All: viewer, checker, rooter, client, moderator, superuser, admin, user
Last: viewer, checker, rooter