Future<T>.value constructor

  1. [FutureOr<T>? value]

Creates a future completed with value.

If value is a future, the created future waits for the value future to complete, and then completes with the same result. Since a value future can complete with an error, so can the future created by Future.value, even if the name suggests otherwise.

If value is not a Future, the created future is completed with the value value, equivalently to new Future<T>.sync(() => value).

If value is omitted or null, it is converted to FutureOr<T> by value as FutureOr<T>. If T is not nullable, then a non-null value must be provided, otherwise the construction throws.

Use Completer to create a future now and complete it later.


Future<int> getFuture() {
 return Future<int>.value(2021);

final result = await getFuture();


factory Future.value([FutureOr<T>? value]) {
  return new _Future<T>.immediate(value == null ? value as T : value);