Returns true if the collection contains an element equal to element
.
This operation will check each element in order for being equal to element
, unless it has a more efficient way to find an element equal to element
.
The equality used to determine whether element
is equal to an element of the iterable defaults to the Object.== of the element.
Some types of iterable may have a different equality used for its elements. For example, a Set may have a custom equality (see Set.identity) that its contains
uses. Likewise the Iterable
returned by a Map.keys call should use the same equality that the Map
uses for keys.
bool contains(Object element) { int length = this.length; for (int i = 0; i < length; i++) { if (this[i] == element) return true; if (length != this.length) { throw new ConcurrentModificationError(this); } } return false; }
© 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/ListMixin/contains.html