JsonDocument::size()
Description
If the root of the JsonDocument is an object, JsonDocument::size() returns the number of key-value pairs in the object (same as JsonObject::size())
If the root of the JsonDocument is an array, JsonDocument::size() returns the number of elements in the array (same as JsonArray::size())
In all other cases, JsonDocument::size() returns 0
Internally, this function walks a linked-list to count the elements, so its time complexity is O(n).
Signature
size_t size() const;
Example
JsonDocument doc;
object["hello"] = "world";
Serial.println(object.size()); // 1
