arduinojson.h arduino library code example
Example: ArduinoJson.h
DynamicJsonDocument doc(1024);
doc["sensor"] = "gps";
doc["time"] = 1351824120;
doc["data"][0] = 48.756080;
doc["data"][1] = 2.302038;
serializeJson(doc, Serial);
// This prints:
// {"sensor":"gps","time":1351824120,"data":[48.756080,2.302038]}