flatMap

Alias for mergeMap.

Signature

flatMap(project: (value: T, index: number) => ObservableInput): OperatorFunction

What it does

Projects each value into an inner Observable and merges the results in parallel. It's the old name for mergeMap.

When to use

Only for supporting legacy code. In new code use mergeMap to avoid the deprecated API.

See also

mergeMap, concatMap, switchMap