Chapter quiz · Services & Concurrency

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8 questions on Services & Concurrency. Pass 70% to clear the chapter.

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Quiz

Services & Concurrency — Chapter Quiz

Eight questions on services, the run loop, ember-concurrency tasks, and dependency injection.

0/ 9

Question 1
1
How do you inject a service into a component or route?
A@inject(serviceName)B@service name (modern) or @service() nameC@import(serviceName)Dthis.use(serviceName)
import { service } from '@ember/service' then @service router injects the service onto this.router. The legacy inject from @ember/service works too.
Question 2
2
What is the Ember run loop?
AA WebGL render loopBA scheduler that batches reactive work into ordered queuesCA hot-module-replacement loopDA loop for HTTP polling
The run loop coordinates rendering, actions, and async settlement into a small set of ordered queues — fewer redraws, predictable ordering, settled tests.
Question 3
3
Which ember-concurrency modifier cancels prior runs and keeps only the latest?
A.drop()B.enqueue()C.restartable()D.keepLatest()
restartable() cancels any running instance and starts a new one — ideal for typeahead search where stale results should not win.
Question 4
4
ember-concurrency tasks are AbortController-aware and cancel cleanly on route transitions.
TTrueFFalse
Tasks tie themselves to the host (component, service) and cancel when the host is destroyed. Coordination is built-in.
Question 5
5
What does the router service provide?
AtransitionTo, currentURL, currentRouteName and route eventsBA direct WebSocket to the serverCLocal storage accessDA logger
Inject @service router to navigate (transitionTo), inspect the current location, and subscribe to routeDidChange / routeWillChange events.
Question 6
6
Ember services are singletons — every consumer that injects the same service receives the ___ instance.
Services are instantiated once per app and shared across all consumers — the canonical place to keep app-wide state.
Question 7
7
Which Ember services come built in?
Select all that apply.
ArouterBstore (from Ember Data)Cfastboot (with the addon installed)DreduxEintl (with ember-intl installed)
router is always available. store, fastboot, and intl come from their respective addons. There is no built-in redux service.
Question 8
8
What is the owner in Ember?
AThe dependency-injection container that resolves factories like services and routesBThe currently signed-in userCA wrapper around localStorageDThe git commit author
The owner is the DI container — getOwner(this).lookup('service:foo') retrieves any factory by full name. this.owner inside tests is this object.