RxJs Book
  • Introduction
  • Summary
    • Why RxJS?
    • RxJS Design Guidelines
      • Introduction
      • When To Use RxJS
      • The RxJS Contract
      • Using RxJS
      • Operator Implementations
    • Getting Started With RxJS
      • What Are The Reactive Extensions?
      • Exploring Major Concepts In RxJS
      • Creating And Querying Observable Sequences
        • Creating And Subscribing To Simple Observable Sequences
        • Bridging To Events
        • Bridging To Callbacks
        • Bridging To Promises
        • Generators And Observable Sequences
        • Querying Observable Sequences
        • Error Handling With Observable Sequences
        • Transducers With Observable Sequences
        • Backpressure With Observable Sequences
        • Operators By Category
      • Subjects
      • Scheduling And Concurrency
      • Testing And Debugging
      • Implementing Your Own Operators
    • How Do I...?
      • How Do I Wrap An Existing API?
      • How Do I Integrate jQuery With RxJS?
      • How Do I Integrate Angular.js With RxJS?
      • How Do I Create A Simple Event Emitter?
    • Mapping RxJS From Different Libraries
      • For Bacon.js Users
      • For Async.js Users
    • Config
      • Promise
      • useNativeEvents
    • Helpers
      • defaultComparer
      • defaultSubComparer
      • defaultError
      • identity
      • just
      • isPromise
      • noop
      • pluck
    • Observable
      • Observable Methods
        • amb
        • case
        • catch
        • combineLatest
        • concat
        • create
        • defer
        • empty
        • for | forIn
        • forkJoin
        • from
        • fromCallback
        • fromEvent
        • fromEventPattern
        • fromNodeCallback
        • fromPromise
        • generate
        • generateWithAbsoluteTime
        • generateWithRelativeTime
        • if
        • interval
        • isObservable
        • just | return
        • merge
        • mergeDelayError
        • never
        • of
        • ofWithScheduler
        • onErrorResumeNext
        • pairs
        • range
        • repeat
        • spawn
        • start
        • startAsync
        • throw
        • timer
        • toAsync
        • using
        • when
        • while | whileDo
        • wrap
        • zip
      • Observable Instance Methods
        • amb
        • and
        • asObservable
        • average
        • buffer
        • bufferWithCount
        • bufferWithTime
        • bufferWithTimeOrCount
        • catch
        • combineLatest
        • concat
        • concatAll
        • concatMapObserver | selectConcatObserver
        • controlled
        • count
        • debounce
        • defaultIfEmpty
        • delay
        • delaySubscription
        • dematerialize
        • distinct
        • distinctUntilChanged
        • do | doAction | tap
        • doOnCompleted | tapOnCompleted
        • doOnError | tapOnError
        • doOnNext | tapOnNext
        • doWhile
        • elementAt
        • every
        • expand
        • extend | manySelect
        • filter | where
        • finally
        • find
        • findIndex
        • first
        • flatMap | selectMany
        • flatMapConcat | concatMap
        • flatMapFirst | selectSwitchFirst
        • flatMapLatest
        • flatMapObserver | selectManyObserver
        • flatMapWithMaxConcurrent
        • forkJoin
        • groupBy
        • groupByUntil
        • groupJoin
        • ignoreElements
        • includes
        • indexOf
        • isEmpty
        • join
        • jortSort
        • jortSortUntil
        • last
        • lastIndexOf
        • let | letBind
        • map | select
        • materialize
        • max
        • maxBy
        • merge
        • mergeAll
        • min
        • minBy
        • multicast
        • observeOn
        • onErrorResumeNext
        • pairwise
        • partition
        • pausable
        • pausableBuffered
        • pipe
        • pluck
        • publish
        • publishLast
        • publishValue
        • reduce
        • repeat
        • replay
        • retry
        • retryWhen
        • scan
        • sequenceEqual
        • share
        • shareReplay
        • shareValue
        • single
        • singleInstance
        • skip
        • skipLast
        • skipLastWithTime
        • skipUntil
        • skipUntilWithTime
        • skipWhile
        • skipWithTime
        • slice
        • some
        • startWith
        • subscribe | forEach
        • subscribeOn
        • subscribeOnCompleted
        • subscribeOnError
        • subscribeOnNext
        • sum
        • switch
        • switchFirst
        • take
        • takeLast
        • takeLastBuffer
        • takeLastBufferWithTime
        • takeLastWithTime
        • takeUntil
        • takeUntilWithTime
        • takeWhile
        • takeWithTime
        • thenDo
        • throttle
        • throttleLatest | sample
        • timeInterval
        • timeout
        • timestamp
        • toArray
        • toMap
        • toPromise
        • toSet
        • transduce
        • window
        • windowWithCount
        • windowWithTime
        • windowWithTimeOrCount
        • withLatestFrom
        • zip
        • zipIterable
    • Observer
      • Observer Methods
        • create
        • fromNotifier
      • Observer Instance Methods
        • asObserver
        • checked
        • notifyOn
        • onCompleted
        • onError
        • onNext
        • toNotifier
    • Notification
      • Notification Methods
        • createOnNext
        • createOnError
        • createOnCompleted
      • Notification Instance Methods
        • accept
        • toObservable
      • Notification Properties
        • exception
        • hasValue
        • kind
        • value
    • Subjects
      • Rx.AsyncSubject
      • Rx.BehaviorSubject
      • Rx.ReplaySubject
      • Rx.Subject
    • Schedulers
      • Rx.HistoricalScheduler
      • Rx.Scheduler
      • Rx.VirtualTimeScheduler
    • Disposables
      • Rx.CompositeDisposable
      • Rx.Disposable
      • Rx.RefCountDisposable
      • Rx.SerialDisposable
      • Rx.SingleAssignmentDisposable
    • Testing
      • Rx.ReactiveTest
      • Rx.Recorded
      • Rx.Subscription
      • Rx.TestScheduler
    • Bindings
      • DOM
        • Ajax
          • ajax
          • ajaxCold
          • get
          • get_Json
          • post
        • JSONP
          • jsonpRequest
          • jsonpRequestCold
        • Web Sockets
          • fromWebSocket
        • Web Workers
          • fromWebWorker
        • Mutation Observers
          • fromMutationObserver
        • Geolocation
          • getCurrentPosition
          • watchPosition
        • Schedulers
          • requestAnimationFrame
          • mutationObserver
      • jQuery
      • AngularJS
        • Factories
          • rx
          • observeOnScope
        • Observable Methods
          • safeApply
        • $rootScope Methods
          • $toObservable
          • $eventToObservable
          • $createObservableFunction
      • Facebook React
      • Ractive.js
      • Node.js
        • Callback Handlers
          • fromCallback
          • fromNodeCallback
        • Event Handlers
          • fromEvent
          • toEventEmitter
        • Stream Handlers
          • fromStream
          • fromReadableStream
          • fromWritableStream
          • fromTransformStream
          • writeToStream
  • Recipes
  • Which Operator do I use?
    • Creation Operators
    • Instance Operators
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  • Returns
  • Example
  • Not empty
  • Empty

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  1. Summary
  2. Observable
  3. Observable Instance Methods

isEmpty

Determines whether an observable sequence is empty.

Returns

(Observable): An observable sequence containing a single element determining whether the source sequence is empty.

Example

Not empty

Empty

PreviousindexOfNextjoin

Last updated 5 years ago

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