Which Operator to Use? - Creation Operators

Use this page to find the creation operator implemented by the Observable type that fits your needs:

Static methods

I want to create a new sequence	using custom logic			Observable.create
		that works like a for-loop		Observable.generate
			and emits the values over time	Observable.generateWithRelativeTime
			and emits the values over time	Observable.generateWithAbsoluteTime
	that returns a value			Observable.return/just
	that returns a value	multiple times		Observable.repeat
	that throws an error			Observable.throw
	that completes			Observable.empty
	that never does anything			Observable.never
	from an event			Observable.fromEvent
	from an event	that uses custom functions to add and remove event handlers		Observable.fromEventPattern
	from an ES6 Promise			Observable.fromPromise
	that iterates	over the values in an array		Observable.fromArray
		over the values in an array	of object key/values	Observable.pairs
		of asynchronous elements		Observable.for
		over values in a numeric range		Observable.range
		over the values in an iterable, array or array-like object		Observable.from
		over arguments		Observable.of
	that emits values on a timer			Observable.interval
	that emits values on a timer	with an optional initial delay		Observable.timer
	that calls a function with no arguments		on a specific scheduler	Observable.start
	that calls a function with no arguments		asynchronously	Observable.startAsync
	decided at subscribe-time	based on a boolean condition		Observable.if
		from a pre-set set of sequences		Observable.case
		using custom logic		Observable.defer
		using custom logic	that depends on a resource	Observable.using
I want to wrap a function			and yield the result in a sequence	Observable.toAsync
	which accepts a callback			Observable.fromCallback
	which accepts a Node.js callback			Observable.fromNodeCallback
I want to combine multiple sequences	and only receive values from the sequence that yields a value first			Observable.amb
	and be notified when all of them have finished			Observable.forkJoin
	and output the values from all of them			Observable.merge
	in order	reusing the latest value when unchanged		Observable.combineLatest
	in order	using each value only once		Observable.zip
	by subscribing to each in order	when the previous sequence completes		Observable.concat
		when the previous sequence errors		Observable.catch
		regardless of whether the previous sequence completes or errors		Observable.onErrorResumeNext
	by responding to different combinations of values (join calculus)			Observable.when