Remove chars but stay first

<?php
$string = 'Hello - Im - iZerang - the best - one!'; // phrase

function stripChars($a, $b = '', $c = 0) {
    $get = explode("-", $a);
    if(empty($get))
        return $a;
    foreach($get as $word) {
        ++$c;
        $b .= $word;
        if($c == 1)
            $b .= ' - ';
    }
    return $b;
}

echo stripChars($string); // call function
// result: Hello - Im iZerang the best one!
?>