PHP 7.1.0 Release Candidate 3 Released

trait_exists

(PHP 5 >= 5.4.0, PHP 7)

trait_existsChecks if the trait exists

Beschreibung

bool trait_exists ( string $traitname [, bool $autoload ] )

Parameter-Liste

traitname

Name of the trait to check

autoload

Whether to autoload if not already loaded.

R├╝ckgabewerte

Returns TRUE if trait exists, FALSE if not, NULL in case of an error.

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User Contributed Notes 2 notes

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10
Lubaev.K
3 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
-1
valerio dot bozzolan at gmail dot com
8 months 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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