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

down

Lubaev.K ¶

11 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!!!

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astinus dot eberhard at gmail dot com ¶

7 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)

down

-1

valerio dot bozzolan at gmail dot com ¶

8 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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