JsonDecode

JSON text as a value.

The reverse of JsonEncode: an object becomes a table with text keys, an array a table with the keys 1 to n, and a JSON null inside them leaves the place empty (in an array the other values keep their positions). The game’s Lua keeps its numbers as 32-bit floats, so an integer beyond 16777216 (2^24) - an id, a large sum - cannot be held exactly and comes back as a text of its digits; convert it with tonumber only if you know it is small enough, or keep it as the text it is.

A null on its own gives nil, so a nil result alone does not say the text was wrong - look at the second value. Text that is not valid JSON, is more than 32 levels deep or is over 1 MB gives nil and the reason. Nothing in the text can run anything: what comes back is data. It works in every game, with or without the web layer.

Syntax

JsonDecode(text)

Parameter	Type
text	string	one JSON value

Returns

any, string | nil - the value - or nil and the reason when the text could not be read

Example

local value, why = JsonDecode('{"id":7,"items":["sword","bread"]}')
if value then print(value.items[2]) else print("bad JSON: " .. why) end   --> bread

See also

JsonEncode · OnWebEvent · the Web interface group of the index