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/Dart 2

single property

E single

Checks that this iterable has only one element, and returns that element.

Throws a StateError if this is empty or has more than one element.

Implementation

E get single {
  if (length > 1) throw IterableElementError.tooMany();
  Iterator<E> it = iterator;
  if (!it.moveNext()) throw IterableElementError.noElement();
  E result = it.current;
  return result;
}

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/2.0.0/dart-collection/SetMixin/single.html