This section explains operators you can use to combine multiple Observables.

• startWith( ) — emit a specified sequence of items before beginning to emit the items from the Observable
• merge( ) — combine multiple Observables into one
• mergeDelayError( ) — combine multiple Observables into one, allowing error-free Observables to continue before propagating errors
• zip( ) — combine sets of items emitted by two or more Observables together via a specified function and emit items based on the results of this function
• (rxjava-joins) and( ), then( ), and when( ) — combine sets of items emitted by two or more Observables by means of Pattern and Plan intermediaries
• combineLatest( ) — when an item is emitted by either of two Observables, combine the latest item emitted by each Observable via a specified function and emit items based on the results of this function
• join( ) and groupJoin( ) — combine the items emitted by two Observables whenever one item from one Observable falls within a window of duration specified by an item emitted by the other Observable
• switchOnNext( ) — convert an Observable that emits Observables into a single Observable that emits the items emitted by the most-recently emitted of those Observables

(rxjava-joins) — indicates that this operator is currently part of the optional rxjava-joins package under rxjava-contrib and is not included with the standard RxJava set of operators