php var_dump(); result php string(4) "1"

when i using php var_dump($result); it's give me string(4) "1"; i'm confused; why that's string length can be 4,it's looks like just the string '1'; Then i debug the result in function

        var_dump(ord($return).'|'.ord('1').'|');
        var_dump(chr(ord($return)));
        var_dump($return);exit;

the output is

string(7) "239|49|" string(1) "ï" string(4) "1"

then i guess the result has some unvisible chars; how can i parse the result to make $return==1 ? eg. clean the unvisible chars.

anyone can help me?

update: when i json_encode($return); it's output "\ufeff1"

i'm using php5.4 Linux ub136 3.2.0-52-generic #78-Ubuntu

here's my function..

function dfopen($url, $limit = 0, $post = '', $cookie = '', $bysocket = FALSE   , $ip = '', $timeout = 15, $block = TRUE, $encodetype  = 'URLENCODE') {
    //error_log("[uc_server]\r\nurl: $url\r\npost: $post\r\n\r\n", 3, 'c:/log/php_fopen.txt');
    $return = '';
    $matches = parse_url($url);
    $host = $matches['host'];
    $path = $matches['path'] ? $matches['path'].($matches['query'] ? '?'.$matches['query'] : '') : '/';
    $port = !empty($matches['port']) ? $matches['port'] : 80;

    if($post) {
        $out = "POST $path HTTP/1.0\r\n";
        $out .= "Accept: */*\r\n";
        //$out .= "Referer: $boardurl\r\n";
        $out .= "Accept-Language: zh-cn\r\n";
        $boundary = $encodetype == 'URLENCODE' ? '' : ';'.substr($post, 0, trim(strpos($post, "\n")));
        $out .= $encodetype == 'URLENCODE' ? "Content-Type: application/x-www-form-urlencoded\r\n" : "Content-Type: multipart/form-data$boundary\r\n";
        $out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";
        $out .= "Host: $host:$port\r\n";
        $out .= 'Content-Length: '.strlen($post)."\r\n";
        $out .= "Connection: Close\r\n";
        $out .= "Cache-Control: no-cache\r\n";
        $out .= "Cookie: $cookie\r\n\r\n";
        $out .= $post;
    } else {
        $out = "GET $path HTTP/1.0\r\n";
        $out .= "Accept: */*\r\n";
        //$out .= "Referer: $boardurl\r\n";
        $out .= "Accept-Language: zh-cn\r\n";
        $out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";
        $out .= "Host: $host:$port\r\n";
        $out .= "Connection: Close\r\n";
        $out .= "Cookie: $cookie\r\n\r\n";
    }

    if(function_exists('fsockopen')) {
        $fp = @fsockopen(($ip ? $ip : $host), $port, $errno, $errstr, $timeout);
    } elseif (function_exists('pfsockopen')) {
        $fp = @pfsockopen(($ip ? $ip : $host), $port, $errno, $errstr, $timeout);
    } else {
        $fp = false;
    }

    if(!$fp) {
        return '';
    } else {
        stream_set_blocking($fp, $block);
        stream_set_timeout($fp, $timeout);
        @fwrite($fp, $out);
        $status = stream_get_meta_data($fp);
        if(!$status['timed_out']) {
            while (!feof($fp)) {
                if(($header = @fgets($fp)) && ($header == "\r\n" ||  $header == "\n")) {
                    break;
                }
            }

            $stop = false;
            while(!feof($fp) && !$stop) {
                $data = fread($fp, ($limit == 0 || $limit > 8192 ? 8192 : $limit));
                $return .= $data;
                if($limit) {
                    $limit -= strlen($data);
                    $stop = $limit <= 0;
                }
            }
        }
        @fclose($fp);
        return $return;
    }
}