Because the interface side of the requirements, with js data processing, so the need for PHP program from the database after the value assigned to the js array. I have not found a good way, because the data encoding of the PHP array and the encoding format of the JS array are not the same, can not be directly output.

After a search on the Internet, the solution was found:

The PHP library provides functions for encoding/decoding JSON: json_encode() and json_decode(), which make it easy to pass arrays or objects to javascript. Note: JSON extensions are only bound to PHP beyond 5.2.

**Write in PHP as follows: **

$arr = array('1',array('2','3'),array('new','old'));
$new_arr = json_encode($arr);//The output of new_arr is; [" 1 ", "2", "3"], [" new ", "old"]]  
echo "var data =". $new_arr;

After referring to the above PHP file in the page, js can directly operate on the data.