How to get name of the constant?

Here's what I did to achieve it. Inspired by Jan Hancic.

class ErrorCode
{
    const COMMENT_NEWCOMMENT_DISABLED = -4;
    const COMMENT_TIMEBETWEENPOST_ERROR = -3;
    /**
     * Get error message of a value. It's actually the constant's name
     * @param integer $value
     * 
     * @return string
     */
    public static function getErrorMessage($value)
    {
        $class = new ReflectionClass(__CLASS__);
        $constants = array_flip($class->getConstants());

        return $constants[$value];
    }
}

I know this is an old question and all, but I still feel that I have some useful input. I implemented this using an abstract class that all my enums extend. The abstract class contains a generic toString() method;

abstract class BaseEnum{
    private final function __construct(){ }

    public static function toString($val){
        $tmp = new ReflectionClass(get_called_class());
        $a = $tmp->getConstants();
        $b = array_flip($a);

        return ucfirst(strtolower($b[$val]));
    }
}

//actual enum
final class UserType extends BaseEnum {
    const ADMIN = 10;
    const USER = 5;
    const VIEWER = 0;
}

This way you can get a human readable string to use in output, on every enum that extends the base enum. Furthermore, your implementation of the enum, being final, cannot be extended and because the constructor in the BaseEnum is private it can never be instantiated.

So for instance, if you show a list of all usernames with their types you can do something like

foreach($users as $user){
    echo "<li>{$user->name}, ".UserType::toString($user->usertype)."</li>";
}

class OrderStatus
{
    public const PENDING = 1;
    public const PROCESSED  = 2;

    public static function getStatusCode($value)
    {
        $class = new ReflectionClass(__CLASS__);
        $constants = array_flip($class->getConstants());

        return $constants[$value] ?? null;
    }

    // OrderStatus::getStatusCode(1); // 'PENDING'

}