Operator
An RxJS operator is a composable function that transforms or combines observables to produce a new observable or observable transformation.
The Joy of JavaScript
A composable function or transformation that processes an observable sequence or stream element by element.
- How it is used
- Processes Observable events in pipelines before subscribers receive them.
- How deep it goes
- Builds custom map, filter, reduce, and skip operators, including subscription, notification, composition, and cancellation mechanics.
- Examples
- Uses random-number streams, mapped number sequences, nested pipelines, and a skip-filter-map-reduce calculation producing 20.
- What you can do after
- Build it from scratch by implementing custom operators that transform, select, accumulate, or suppress Observable emissions.
Modern Angular
An RxJS operator is a function that transforms or composes observables, typically used with the pipe method to produce a new observable.
- How it is used
- Supports reactive event, HTTP, form-change, and state streams by manipulating, transforming, and combining observables.
- How deep it goes
- Explains `map` emission-by-emission and `pipe` through unary function composition, while deferring signals comparisons.
- Examples
- Demonstrates `of(1, 2, 3)`, `merge`, `map` multiplication, and compose-versus-pipe utility functions.
- What you can do after
- Apply it via RxJS `pipe` and `map` to transform observable emissions and compose stream behavior.
Related concepts
- RxJSused by · RxJS is a JavaScript library implementing ReactiveX with observables and operators for composing asynchronous and event-based programs.
- custom RxJS operatorincludes · A custom RxJS operator is an application-defined operator that transforms or otherwise composes observable sequences.
- combineLatest operatorincludes · The RxJS combineLatest operator combines source observables and emits whenever one emits after every source has emitted at least once.
- observableuses · An observable is a source that emits a sequence of values or notifications over time to consumers that subscribe to it.
- streaminguses · Streaming is the incremental handling of a sequence of data items, including their processing, transfer, or consumption as they become available.
- higher-order functionuses · A higher-order function is a function that accepts functions as arguments, returns functions as results, or both.
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