ReflectionClass::getConstants

(PHP 5, PHP 7)

ReflectionClass::getConstants获取一组常量

说明

public ReflectionClass::getConstants ( void ) : array

获取某个类的全部已定义的常量,不管可见性如何定义。

Warning

本函数还未编写文档,仅有参数列表。

参数

此函数没有参数。

返回值

常量的数组,常量名是数组的键,常量的值是数组的值。

参见

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User Contributed Notes 6 notes

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27
davide dot renzi at gmail dot com
5 years ago
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();
    }
}
?>
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10
Sandor Toth
2 years ago
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'
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6
Panni
11 months ago
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"
}

?>
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1
shgninc at gmail dot com
5 years ago
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
}
}
?>
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2
djhob1972 at yahoo dot com dot au
9 years ago
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!
up
0
dmitrochenkooleg at gmail dot com
6 months ago
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
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