__invoke() Method

The __invoke() magic method is called when the code calls an object as a function name. This type of class is also called a functor.

The method is able to take an arbitrary number of arguments, as usual.

When a class has the __invoke class, it is possible to can a method without mentioning its name: the object is the method.

__invoke` is also considered as the anonymous method: it is called without using its name.

<?php
// extracted from the PHP manual
     class CallableClass
     {
         public function __invoke($x)
         {
             var_dump($x);
         }
     }

     $obj = new CallableClass;
     $obj(5);
     var_dump(is_callable($obj));
?>

Documentation

See also PHP __invoke

Related : Magic Methods, SOLID