What is the Dart “Expando” feature about, what does it do?

Question

Have been seeing the term \"Expando\" used recently with Dart. Sounds interesting. The API did not provide much of a clue to me.

An example or two could be most he

Answer 1

Just to clarify the difference between expando and maps: as reported in the groups, expando has weak references.
This means that a key can be garbage collected even if it's still present in the expando (as long as there are no other references to it).

For all other intents and purposes it's a map.