Bot Math

function doMath($bot,$user){
        $mathString = "";
        for($i=4;$i<=count($bot->ex)-1;$i++){
            $mathString .= $bot->ex[$i];
        }
//        $mathString = $this->getParams($bot);
        $mathString = str_replace(array("[","]"," "),array("(",")",""),$mathString);
        if(!$mathString || preg_match("/[a-zA-Z]+/",$mathString)){
            $msg = "No letters in math, I'm not doing algebra for you.";
        }else{
            $msg = "Answer: " . eval("return $mathString;");
        }
        $bot->send_message($msg);
    }