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
that returns a value Observable.return/just
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
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
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
with an optional initial delay Observable.timer
that calls a function with no arguments on a specific scheduler Observable.start
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
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
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

See Also