Попробуйте это:
$array = Array ( Array("topic_title" => "aatoipic","title" => "new toipic"),Array("event_title" => "Test Event","title" => "Test Event"),Array("topic_title" => "Welcome!", "title" => "Welcome!"),Array("entry_title" => "sdasdad","title" => "p",),Array("event_title" => "red","title" => "k",),Array("event_title" => "sa","title" => "sa"),Array("event_title" => "sadasd","title" => "d"),Array("topic_title" => "gff", "title" => "gff"),Array( "topic_title" => "new toipic","title" => "h"));
$arr = $array;
$sort = array();
foreach($arr as $k=>$v) {
$sort['title'][$k] = $v['title'];
}
array_multisort($sort['title'], SORT_ASC, $arr);
echo "<pre>";
print_r($arr);
Вывод придет:
Array ( [0] => Array ( [event_title] => Test Event [title] => Test Event ) [1] => Array ( [topic_title] => Welcome! [title] => Welcome! ) [2] => Array ( [event_title] => sadasd [title] => d ) [3] => Array ( [topic_title] => gff [title] => gff ) [4] => Array ( [topic_title] => new toipic [title] => h ) [5] => Array ( [event_title] => red [title] => k ) [6] => Array ( [topic_title] => aatoipic [title] => new toipic ) [7] => Array ( [entry_title] => sdasdad [title] => p ) [8] => Array ( [event_title] => sa [title] => sa ) )