This is the detailed documentation of every class and function of the ArduinoJson library. Some parts have been simplified to be easier to understand, so if you look at the source code, you might see some differences.

Entities

JsonArray
Stores an array of JsonVariant
JsonObject
Stores a collection of key-value pair where each key is a string and each value is a JsonVariant
JsonVariant
Stores any kind of value allowed in a JSON document: int, float, array, object…
JsonDocument
Owns the memory for JsonArray and JsonObject

JSON serialization / deserialization

deserializeJson()
Deserialize a JSON document into a JsonDocument.
serializeJson()
Serializes a JsonDocument into a minified JSON document
serializeJsonPretty()
Serializes a JsonDocument into a prettyfied JSON document
measureJson()
Computes the size of the document that serializeJson() produces
measureJsonPretty()
Computes the size of the document that serializeJsonPretty() produces

MessagePack serialization / deserialization

deserializeMsgPack()
Deserialize a MessagePack document into a JsonDocument
serializeMsgPack()
Serializes a JsonDocument into a MessagePack document
measureMsgPack()
Computes the size of the document that serializeMsgPack() produces

Compile time configuration

ARDUINOJSON_DEFAULT_NESTING_LIMIT
Defines the default nesting limit
ARDUINOJSON_ENABLE_ARDUINO_STRING
Controls the support of the Arduino String class
ARDUINOJSON_ENABLE_PROGMEM
Controls the support of Flash strings
ARDUINOJSON_ENABLE_STD_STRING
Controls the support of the std::string class
ARDUINOJSON_NEGATIVE_EXPONENTIATION_THRESHOLD
Controls the exponentiation of small floating-point values
ARDUINOJSON_POSITIVE_EXPONENTIATION_THRESHOLD
Controls the exponentiation of large floating-point values
ARDUINOJSON_USE_DOUBLE
Selects the storage type for floating-point values
ARDUINOJSON_USE_LONG_LONG
Selects the storage type for integral values

Misc

ARDUINOJSON_VERSION
Tells which version of ArduinoJson is installed
serialized()
Allows to insert preformatted pieces of JSON or MsgPack in a document