PHP Array Group By

gistfile1.php

<?php

$str = array("a","a","a","b","b","c","d","d","d");

foreach( array_count_values($str) as $item => $count ) {
    for( $i = 0; $i < $count; $i++ ) {
        echo $item."<br/>";
    }
    echo "<hr/>";
}

?>