Undefined json_encode function?

For some strange reason one of my php scripts at work stopped functioning and was throwing a fatal error complaining that the json_encode() function was undefined. I thought this was a bit strange since I could of sworn the previous week it was working fine. I am using the json_encode() function to allow javascript to properly parse data that it requests via AJAX. It allows the parsing of database information in a more efficient manner than other methods I have seen.

It seems that the version of PHP previous to 5.2 do not have the json_encode() function available and this can be a bit of a pain when working with ajax scripts that request information from a MySQL database. I hopefully have found a quick solution by recreating the proper output for those who are running PHP versions 5.1 and older.


$qry = mysql_query("SELECT * FROM blah");
$results = mysql_fetch_array($qry);

$json = “{”;
foreach ($results as $field => $value) {
$json = $json . ‘”‘ . $field .’”:”‘. $value .’”,’;
}
$json = substr($json, 0, strlen($json)-1);
$json = $json . ‘}’;

echo $json;

What this does is it will go through your previous MySQL query results and insert the field name along with its value into a string which can then be outputted in the proper format for JavaScript to properly parse the data.

This seems to be the quickest way to recreate a json_encode output when it is not available to those who are using PHP version less than 5.2. I have seen various PHP classes on the internet that are bloated and do far more than they really should when you’re just trying to create the function. One PHP class I saw  had 50 lines of code! My above example to recreate the function is 6 lines of code (doesn’t include the MySQL lines). Another PHP class I found was broken in various spots and was said to be ‘complete’ and ‘functional’. Oh well, I hope my example helps people out there who need to fix scripts to work with older versions.