Special Types¶

PHP defines some special types.

mixed : any type
void : no returned value
callable : may be used as a callback
iterable : may be used with foreach(), including array
never : never returns
object : object of any class
parent : any of the parent class of the current class, excluding it
self : the current class
static : the current called class

Other special types are the scalar types.

<?php
function foo(iterable $i) : never {
    foreach ($i as $j) {
        echo $j;
    }

    die();
}

?>

Related : Type System

Added in PHP 7.0