JavaScript Object Notation, otherwise known as JSON, is a commonly-used data format on the web. It is a text-based format insofar that JSON is expressed as a human-readable string of symbols, letters, and numbers. Its use has grown over the years such that it is frequently used through software engineering. JSON hits the sweet spot of simple, human-readable, and general enough to express nested datasets. JSON does have its limits however: it is not memory-efficient, it can be slow to parse (load), it is hard to write by hand, and JSON cannot express cylical self-reference. In reality, JSON is more than adequate for most data storage in GameMaker and you'll find yourself using it a lot for everything from savedata, to REST APIs, to item databases.

JSON in GameMaker used to be handled by the nested ds_list and ds_map constructions. Old-style GameMaker JSON could be converted from lists/maps to a string and back again using json_encode() and json_decode(). As of GameMaker 2.3, the preference these days is to represent JSON data as arrays and structs rather than lists and maps, and the functions json_stringify() and json_parse() should be used instead. These functions aren't perfect, however, and there is room for improvement.

SNAP's JSON stringification functions (SnapToJSON() and SnapBufferWriteJSON()) allow you to customise the accuracy of floating point numbers and the appearance of the resulting JSON string. The former option works around a flaw in json_stringify() where only two decimal places are stored for a decimal number, and the later makes JSON output much easier to read. Both behaviours incur a performance and memory penalty but they are often useful, if only during development.

The JSON parser (SnapFromJSON() and SnapBufferReadJSON()) functions cover basic JSON reading as well as allowing for in-line and block comments. This isn't strictly part of the JSON specification, but being able to comment out sections of JSON is a useful feature. SNAP's JSON parser also allows for hanging commas at the end of arrays and objects which is convenient when writing JSON by hand.

Returns: String, the JSON-encoded data

!> Setting any of the optional arguments to true will incur a memory and performance penalty. You will generally only want to turn the optional features on during development.

Returns: Array or struct, the root node of the JSON data

Returns: N/A (undefined)

The JSON string will be inserted into the buffer at the current "head" position, as determined by GameMaker's native buffer_tell() function.

!> Setting any of the optional arguments to true will incur a memory and performance penalty. You will generally only want to turn the optional features on during development.

Returns: Array or struct, the root node of the JSON data

?> If you do not specify an offset then SNAP will modify the buffer's "head" position. This allows you to read sequential data more easily.