Returns the single element that satisfies test
.
Checks elements to see if test(element)
returns true. If exactly one element satisfies test
, that element is returned. If more than one matching element is found, throws StateError. If no matching element is found, returns the result of orElse
. If orElse
is omitted, it defaults to throwing a StateError.
E singleWhere(bool test(E element), {E orElse()}) { E result; bool foundMatching = false; for (E element in this) { if (test(element)) { if (foundMatching) { throw IterableElementError.tooMany(); } result = element; foundMatching = true; } } if (foundMatching) return result; if (orElse != null) return orElse(); throw IterableElementError.noElement(); }
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Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.5.0/dart-collection/IterableMixin/singleWhere.html