FAQ
Parsing succeeds but I can't read the values!
99.999% of the time, this is caused by a confusion between arrays and objects.
This often happens when the JSON contains [{ or :[.
Example 1:
[{"hello":"world"}]
Wrong implementation:
JsonObject& root = jsonBuffer.parseObject(json);
const char* world = root["hello"];
Good implementation:
JsonArray& root = jsonBuffer.parseArray(json);
const char* world = root[0]["hello"];
Example 2:
{"hello":["world"]}
Wrong implementation:
JsonObject& root = jsonBuffer.parseObject(json);
const char* world = root["hello"];
Good implementation:
JsonArray& root = jsonBuffer.parseArray(json);
const char* world = root["hello"][0];
Example 3:
{"hello":[{"new":"world"}]}
Wrong implementation:
JsonObject& root = jsonBuffer.parseObject(json);
const char* world = root["hello"]["new"];
Good implementation:
JsonArray& root = jsonBuffer.parseArray(json);
const char* world = root["hello"][0]["new"];
The ArduinoJson Assistant can generate the program skeleton for you.