Removed in ArduinoJson 6.20: use JsonDocument::operator[] instead.


JsonDocument::getOrAddMember() reproduces JsonObject::getOrAddMember(). It requires that the JsonDocument contains an object, and it can convert the document if needed.

Instead of this function, you can use JsonDocument::operator[] which offers a more intuitive syntax.


JsonVariant getOrAddMember(const char* key);
JsonVariant getOrAddMember(String key);
JsonVariant getOrAddMember(std::string key);
JsonVariant getOrAddMember(const __FlashStringHelper* key);
JsonVariant getOrAddMember(std::string_view key);  // 🆕 (added in 6.18.1)


key: the key of the value in the object.

As usual, ArduinoJson makes a copy of the key in the JsonDocument, except if it’s a const char*.

Return value

If the key is already present in the object, this function returns a JsonVariant that points to the associated value.

If the key is not present in the object, this function adds a new key-value pair to the object and returns a JsonVariant that points to the value. The returned JsonVariant could be null if there were not enough room in the JsonDocument.

See also