function pleac_Doing_Something_with_Every_Element_in_a_List() { foreach ($list as $item) { // do something with $item } // Environment listing example // PHP defines a superglobal $_ENV to provide access to environment // variables. // Beware, array assignment means copying in PHP. You need to use // the reference operator to avoid copying. But we want a copy here. $env = $_ENV; // PHP can sort an array by key, so you don't need to get keys, // and then sort. ksort($env); foreach ($env as $key => $value) { echo "{$key}={$value}\n"; } // Literal translation of Perl example would be: $keys = array_keys($_ENV); sort($keys); foreach ($keys as $key) { echo "{$key}={$_ENV[$key]}\n"; } // This assumes that MAX_QUOTA is a named constant. foreach ($all_users as $user) { $disk_space = get_usage($user); if ($disk_space > MAX_QUOTA) { complain($user); } } // You can't modify array's elements in-place. $array = array(1, 2, 3); $newarray = array(); foreach ($array as $item) { $newarray[] = $item - 1; } print_r($newarray); // Before PHP 5, that is. You can precede the reference operator // before $item to get reference instead of copy. $array = array(1, 2, 3); foreach ($array as &$item) { $item--; } print_r($array); // TODO: explain the old each() and list() iteration construct. // foreach is new in PHP 4, and there are subtle differences. }
/** * Feel free to add more rules. This one is provided as an example. */ protected function enforceRequired($value) { if ($value == null) { complain("is a required value"); } }