$re = '/(?:(?:"([^"}]*)")|(\w+))\s*:\s*(?:(?:"([^"}]*)")|(\w+))/';
$str = '{
"data":" ",
"displayException":"Unable to authenticate user. Please make sure you have an existing account. If you do not, select Register to create an account. Please contact 1-234-567-8910 M-F 9a-5pm CT for further assistance.",
"exception":"UNABLE TO LOGIN",
"success":false,
"failed": true,
id : one_number
}';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php