JSON

Must be included via require.

---

json.encode

Returns a string of JSON.

Parameters

1. data — A boolean, number, string, or table to encode as JSON.
2. pretty — Whether to return a human-readable string of JSON. Defaults to false.

local json = require("json")
local data

data = "Hello, World!"
print(json.encode(data, true))
--> "Hello, World!"

data = {
    key = "Hello, World!",
    nested = {
        nested_key = 1337
    }
}
print(json.encode(data, true))
--> {
-->     "key": "Hello, World!",
-->     "nested": {
-->         "nested_key": 1337
-->     }
--> }

Because Lua tables do not have order guarantees, you can add an __order field to fix the order:

local t = {
    __order = { "a", "b", "c" },
    a = 1,
    b = 2,
    c = 3
}
print(require"json".encode(t)) -- {"a":1,"b":2,"c":3}

The json.null value — assuming you did local json = require("json") — can be used to encode JSON null values.

local json = require("json")

print(json.encode(json.null)) --> null

---

json.decode

Returns multiple potential types. If you pass a serialized boolean, number, or string, then it will return the same type. If you pass a complex JSON object, it will return a table.

Parameters

1. data — The JSON data to decode.
2. flags — Options to augment the return value. Multiple options can be combined with bitwise OR (|). Defaults to 0.
   • json.withnull — decodes JSON null values as json.null instead of nil.
   • json.withorder — adds an __order field to tables of decoded JSON objects. json.encode respects this, so this is perfect for modifying data while preserving order.

local json = require("json")
local data, encoded, decoded

-- Basic Type

data = "Hello, World!"
encoded = json.encode(data, true)
decoded = json.decode(encoded)

assert(decoded == data)
assert(type(decoded) == "string")

-- Complex Type

data = {
    key = "Hello",
    nested = {
        nested_key = 1337
    }
}
encoded = json.encode(data, true)
decoded = json.decode(encoded)

assert(decoded.key == "Hello")
assert(type(decoded) == "table")
assert(decoded.nested.nested_key == 1337)

-- Flags

encoded = [[{
    "null": null,
    "string": "Hello"
}]]
decoded = json.decode(encoded, json.withnull | json.withorder)
assert(decoded.__order[1] == "null")
assert(decoded.null == json.null)
assert(json.encode(decoded, true) == encoded)