Actions & Reducers — Series 2

Preview — 3 of 10 questions

What does this give you beyond a plain reducer?

javascript

export const heroesFeature = createFeature({
  name: 'heroes',
  reducer: createReducer(initialState, on(loaded, (s, { heroes }) => ({ ...s, heroes }))),
});

ANothing; it is a naming convention

BIt registers the feature globally at import time

CIt bundles the feature name, the reducer and generated selectors — selectHeroesState plus one per state property — so the common selectors do not have to be written by hand

DIt replaces effects

What does this return?

javascript

heroes = this.store.selectSignal(selectAllHeroes);

AAn observable that must go through the async pipe

BA promise of the current value

CA snapshot array, read once

DA signal — read as heroes() in the template, with no subscription to manage and no async pipe

Is this valid?

javascript

this.store.subscribe((state) => console.log(state));

ANo — Store has no subscribe

BYes — Store extends Observable<State>, so subscribing yields the whole state on every change. It is valid and almost always the wrong granularity: any change anywhere emits

CYes, and it emits only once

DOnly inside an effect

Answer all 10 questions (7 more), see explanations for every answer, and track your score.