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- // ArduinoJson - arduinojson.org
- // Copyright Benoit Blanchon 2014-2019
- // MIT License
- //
- // This example shows how to deserialize a JSON document with ArduinoJson.
- #include <iostream>
- #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<N> 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<long>();
- 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;
- }
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