As you know var_dump() in addition to value show its data type and length.
Is there any way to log its output to
if you just want to see the var_dump out put in the firebug (client side) without doing any things in Javascript I would recommande using cookies following is an illustration how you can perform it that way:
";
echo $str."\n";
function sendVarDumpToFront( $mixed ){
ob_start();
var_dump($mixed);
$content = ob_get_contents();
ob_end_clean();
setcookie("var_dump",$content);
}
than you can have it in firebug this way:

IMPORTANT
since this way uses cookies you will have to put the var_dump content before outputing any content otherwise this will not work