nodemcu-firmware/docs/en/modules/cjson.md

cjson Module

The JSON support module. Allows encoding and decoding to/from JSON.

Please note that nested tables can require a lot of memory to encode. To catch out-of-memory errors, use pcall().

cjson.encode()

Encode a Lua table to a JSON string.

####Syntax cjson.encode(table)

####Parameters

• table: data to encode

While it also is possible to encode plain strings and numbers rather than a table, it is not particularly useful to do so.

####Returns string:in json format

####Example

ok, json = pcall(cjson.encode, {key="value"})
if ok then
  print(json)
else
  print("failed to encode!")
end

---

cjson.decode()

Decode a JSON string to a Lua table.

####Syntax cjson.decode(str)

####Parameters

• str: The JSON string to decode

####Returns table:Lua representation of the JSON data

####Example

t = cjson.decode('{"key":"value"}')
for k,v in pairs(t) do print(k,v) end

---