Full example

<?php

/** @var \DateTime[] An array of DateTime objects. */
/** @var string[] An array of string objects. */
/** @var callable[] An array of with callable functions or methods. */

/** @var \ArrayObject|\DateTime[] */
$dates = array()

/**
 * @param bool|\DateTime $foo the first argument
 * @return string|null
 */
function bar($foo) { ... }