json_decode

This function decodes a JSON string and converts it into a DS Map, ready for use in GameMaker.

重要 This function - while still valid - has been superseded by the function json_parse, and we recommend that you only use this function for legacy support.

GameMaker creates the necessary DS maps and lists from the JSON, and for cleaning up you only need to delete the top-level map and GameMaker will automatically delete from memory all the maps and lists underneath.
If the JSON to be decoded requires a hierarchy of lists and maps within the central DS map, these are also decoded and created for you, using the following rules (note that these rules apply to the top-level structure only):

• JSON is a single value - returns a DS map with a single entry "default" that is the value
• JSON is an array of objects or values - returns a DS map with a single entry "default" that is a DS list of the objects or values
• JSON is an object - returns a DS map that has the object entries in it

Usage Notes

• This function always returns a DS Map, no matter the type of the top-level element. If this top-level element in the JSON is not an object (either a single value "5" or an array "1, 2, 3, 4"), it will be placed in a DS Map under a key "default". Internal lists decode directly to a DS Map without being enclosed in a DS map.
• If you wrote GameMaker arrays into the top level, or as the contents of a DS map or DS list, these will be decoded as DS lists, not as arrays.
• Normally you'll know what keys the JSON decodes to, if not you can use the ds_map_size, ds_map_find_first and ds_map_find_next functions to get this information.
• You can load JSON files with a maximum nesting limit of 128.

语法:

json_decode(string)

返回:

DS Map or -1 (if it fails)

例子:

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);
    }
}
ds_map_destroy(resultMap);

上面的代码将解码一个 JSON 字符串并解析它以生成一个全局数组。