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) {
for (E e in this) {
if (e == element) return true;
}
return false;
}
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.5.0/dart-core/Iterable/contains.html