// ArduinoJson - arduinojson.org // Copyright Benoit Blanchon 2014-2019 // MIT License // // This example shows how to deserialize a JSON document with ArduinoJson. #include #include "ArduinoJson.h" int main() { // Allocate the JSON document // // Inside the brackets, 200 is the capacity of the memory pool in bytes. // Don't forget to change this value to match your JSON document. // Use arduinojson.org/v6/assistant to compute the capacity. StaticJsonDocument<300> doc; // StaticJsonDocument allocates memory on the stack, it can be // replaced by DynamicJsonDocument which allocates in the heap. // // DynamicJsonDocument doc(200); // JSON input string. // // Using a char[], as shown here, enables the "zero-copy" mode. This mode uses // the minimal amount of memory because the JsonDocument stores pointers to // the input buffer. // If you use another type of input, ArduinoJson must copy the strings from // the input to the JsonDocument, so you need to increase the capacity of the // JsonDocument. char json[] = "{\"sensor\":\"gps\",\"time\":1351824120,\"data\":[48.756080,2.302038]}"; // Deserialize the JSON document DeserializationError error = deserializeJson(doc, json); // Test if parsing succeeds. if (error) { std::cerr << "deserializeJson() failed: " << error.c_str() << std::endl; return 1; } // Fetch values. // // Most of the time, you can rely on the implicit casts. // In other case, you can do doc["time"].as(); const char* sensor = doc["sensor"]; long time = doc["time"]; double latitude = doc["data"][0]; double longitude = doc["data"][1]; // Print values. std::cout << sensor << std::endl; std::cout << time << std::endl; std::cout << latitude << std::endl; std::cout << longitude << std::endl; return 0; }