Create json from array in PHP -

i have little sql code:

try {         $stmt = $conn->prepare("select appid commentroom badgeid=? group appid");         $stmt->execute(array($badgeid));             while ($row = $stmt->fetch(pdo::fetch_assoc)) {                 $row2[$i][0] = $row['appid'];                 $i++;             }         } catch(pdoexception $e) {             echo 'error: ' . $e->getmessage();             $server_dir = $_server['http_host'] . rtrim(dirname($_server['php_self']), '/\\');             header('location: http://' . $server_dir);             exit();     } 

when print out result print(json_encode($row2)); following:

[["0000000021"],["0000000037"],["0000000038"],["0000000039"],["0000000128"],["0000000130"]] 

since have data don't need query database. still need forward in same format java app. when use

$output[] = json_encode($row2); print(json_encode($output)); 

i different output:

["[[\"0000000021\"],[\"0000000037\"],[\"0000000038\"],[\"0000000039\"],[\"0000000128\"],[\"0000000130\"]]"] 

i checked few stackoverflow questions didn't find addresses same problem.

you json encoding twice

$output[] = json_encode($row2); print(json_encode($output)); 

just once:

$output[] = $row2; print(json_encode($output));