Building a string made easier?
Peter Kiss's code works, but it's not fast.

&lt;?php

$tags = $product-&gt;getTags();
$c    = count($tags);
$str  = null;
for ($i = 0; $i &lt; $c; ++$i) {
    if ($str) {
        $str .= ", ";
    }
    $str .= $tags[$i]-&gt;getTag();
}

?&gt;


Yes, it’s not short (and not much different to your solution) but it’s highly efficient and therefor the solution I’d go for.