问题
I think that it is a cold observable (as is the default) but couldn't find a reference to it either in the code or the documentation.
(Sorry if this is asked already, couldn't find something)
回答1:
;TLDR It's a hot observable because both ActionSubject and ReducerManager extend BehaviorSubject which is a hot observable.
As stated in the diagram at https://ngrx.io/guide/store
The store receives events from Actions, and Actions are processed via Reducers. Both ActionSubject (the observable of actions) and ReducerManager (the observable of reducer) inherit BehaviorSubject from RxJs library.
The docs and source code are taken from ngrx/store 4.x https://github.com/ngrx/platform/tree/master/modules/store/src
Hope that help.
来源：https://stackoverflow.com/questions/54629140/is-ngrx-store-a-hot-or-cold-observable