PHP分割textarea每一行的数据

<form id="textarea_test" action="textarea.php" method="post">   
<textarea cols="50" rows="5" name="aa" id="abc" >  
</form>

<?php
$str = $_POST['aa'];
 
//var_dump($str);   
 
//$str = "chenjinle le";   
 
$array = explode("\n", trim($str));   
 
var_dump($array);   
 
?>