<?php
class Comparator {
    public function __get($x) {
        return function($a, $b)use($x) {return strcasecmp($a[$x], $b[$x]);};
    }
}

$_ = new Comparator;

$data = array(
    array('name' => 'xyu', 'length' => '30'),
    array('name' => 'pizda', 'length' => '0'),
    array('name' => 'dzhigurda', 'length' => '200')
);

usort($data, $_->name);

var_dump($data);