JSON (JavaScript Object Notation) is a lightweight data-interchange format which is easy for to read and write, for both people and machines. It is built on two basic structures:

With this function, you can decode a piece of JSON and convert it into a ds_map, ready for use in GameMaker Studio 2. If the JSON to be decoded requires a hierarchy of lists and maps within the central ds_map, these are decoded too and also created for you, using the following rules (note that these rules apply to the top-level structure only):

NOTE: When decoding arrays, there is a map with the key "default" ONLY when an array is the top level structure, and ONLY for that top-level array. Internal lists decode directly to ds_lists without being enclosed in a ds_map.

Normally you would know what keys the JSON decodes to, but if not then you can use the ds_map_size, ds_map_find_first and ds_map_find_next functions to parse the map and get the necessary information.

NOTE: GameMaker Studio 2 creates the necessary ds_maps and lists from the JSON, and for cleaning up you only need to delete the top level map or list and GameMaker Studio 2 will automatically delete from memory all the maps and lists underneath.
IMPORTANT: You cannot have 64bit numbers in your JSON, as they will not work correctly due them not being handled by the JSON format.



Argument Description
string The JSON format string that you are passing to the function for decoding


ds_map id or -1 if it fails


var resultMap = json_decode(requestResult);
var list = ds_map_find_value(resultMap, "default");
var size = ds_list_size(list);
for (var n = 0; n < ds_list_size(list); n++;)
   var map = ds_list_find_value(list, n);
   var curr = ds_map_find_first(map);
   while (is_string(curr))
      global.Name[n] = ds_map_find_value(map, "name");
      curr = ds_map_find_next(map, curr);

The above code will decode a JSON string and parse it to generate a global array.