trait_exists

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

trait_existsPrüft, ob der Trait existiert

Beschreibung

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

Parameter-Liste

trait

Der Name des zu prüfenden Traits

autoload

Ob automatisch geladen werden soll, wenn nicht bereits geladen.

Rückgabewerte

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

add a note add a note

User Contributed Notes 3 notes

up
13
Lubaev.K
9 years ago
<?php
trait 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!!!
up
4
astinus dot eberhard at gmail dot com
5 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)
up
3
valerio dot bozzolan at gmail dot com
6 years ago
What is the default value of $autoload? And in which way traits are autoloaded? Is there something as spl_autoload() for traits?
To Top