This page lists various utility operators for working with Observables.

• materialize( ) — convert an Observable into a list of Notifications
• dematerialize( ) — convert a materialized Observable back into its non-materialized form
• timestamp( ) — attach a timestamp to every item emitted by an Observable
• serialize( ) — force an Observable to make serialized calls and to be well-behaved
• cache( ) — remember the sequence of items emitted by the Observable and emit the same sequence to future Subscribers
• observeOn( ) — specify on which Scheduler a Subscriber should observe the Observable
• subscribeOn( ) — specify which Scheduler an Observable should use when its subscription is invoked
• doOnEach( ) — register an action to take whenever an Observable emits an item
• doOnNext( ) — register an action to call just before the Observable passes an onNext event along to its downstream
• doAfterNext( ) — register an action to call after the Observable has passed an onNext event along to its downstream
• doOnCompleted( ) — register an action to take when an Observable completes successfully
• doOnError( ) — register an action to take when an Observable completes with an error
• doOnTerminate( ) — register an action to call just before an Observable terminates, either successfully or with an error
• doAfterTerminate( ) — register an action to call just after an Observable terminated, either successfully or with an error
• doOnSubscribe( ) — register an action to take when an observer subscribes to an Observable
• 1.x doOnUnsubscribe( ) — register an action to take when an observer unsubscribes from an Observable
• finallyDo( ) — register an action to take when an Observable completes
• doFinally( ) — register an action to call when an Observable terminates or it gets disposed
• delay( ) — shift the emissions from an Observable forward in time by a specified amount
• delaySubscription( ) — hold an Subscriber's subscription request for a specified amount of time before passing it on to the source Observable
• timeInterval( ) — emit the time lapsed between consecutive emissions of a source Observable
• using( ) — create a disposable resource that has the same lifespan as an Observable
• single( ) — if the Observable completes after emitting a single item, return that item, otherwise throw an exception
• singleOrDefault( ) — if the Observable completes after emitting a single item, return that item, otherwise return a default item
• repeat( ) — create an Observable that emits a particular item or sequence of items repeatedly
• repeatWhen( ) — create an Observable that emits a particular item or sequence of items repeatedly, depending on the emissions of a second Observable