Reference · 01

of

Creates an Observable from the given values, then completes.

Signature

of(...values: T[]): Observable

Marble diagram

of(1, 2, 3):  (1 2 3 |)

What it does

Emits each argument in turn synchronously, then sends complete. The subscription runs instantly — no async delays. Each argument passes through the stream exactly once; nothing is grouped or further unwrapped.

When to use

When you need an "instant" stream from a fixed set of values: mocks in tests, default values for combineLatest/startWith, or a short wrapper stream around a value you already have synchronously. Also handy for writing examples and teaching.

Gotcha

of([1, 2, 3]) is a stream of one array, not three values. To unpack the array into three emissions, use from([1, 2, 3]).

of

of

Signature

Marble diagram

What it does

When to use

See also