trait_exists

(PHP 5 >= 5.4.0, PHP 7, PHP 8)

trait_exists — Prüft, ob der Trait existiert

Beschreibung

trait_exists(string $trait, bool $autoload = true): bool

Parameter-Liste

trait: Der Name des zu prüfenden Traits
autoload: Gibt an, ob automatisch geladen werden soll, falls nicht bereits geladen.

Rückgabewerte

Gibt true zurück, wenn die Eigenschaft existiert, andernfalls wird false zurückgegeben.

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User Contributed Notes 3 notes

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Lubaev.K ¶

12 years ago

<?phptrait World {    private static $instance;    protected $tmp;    public static function World()    {        self::$instance = new static();        self::$instance->tmp = get_called_class().' '.__TRAIT__;                return self::$instance;    }}if ( trait_exists( 'World' ) ) {        class Hello {        use World;        public function text( $str )        {            return $this->tmp.$str;        }    }}echo Hello::World()->text('!!!'); // Hello World!!!

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astinus dot eberhard at gmail dot com ¶

8 years ago

Traits are compatible with class autoload mechanism - in fact, if you look at source code of trait_exists function, you will find similar peace of code (see Zend/zend_builtin_functions.c)

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-1

valerio dot bozzolan at gmail dot com ¶

9 years ago

What is the default value of $autoload? And in which way traits are autoloaded? Is there something as spl_autoload() for traits?

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