php - Echo a comma on all but the last value? (result from mysql_fetch_array)

Question

How do I echo a comma on all but the last value? Here's my code:

while ($servdescarrayrow = mysql_fetch_array($servdescarray)) {

    ECHO $servdescarrayrow['serv_desc'].",";
}

Shouldn't this work:

$i = 0;

while ($servdescarrayrow = mysql_fetch_array($servdescarray)) {

    $count = count($servdescarrayrow);
    if ($i < $count) {
    echo $servdescarrayrow['serv_desc'].",";
    $i++;
    }
    else {
        break;
    }
}

Answer 1

Another option:

$values = array();
while ($servdescarrayrow = mysql_fetch_array($servdescarray)) {
    $values[] = $servdescarrayrow['serv_desc'];
}

echo implode(',', $values);