HashSet<T>::IsProperSubsetOf Method (IEnumerable<T>^)
Determines whether a HashSet<T> object is a proper subset of the specified collection.
Assembly: System.Core (in System.Core.dll)
Parameters
- other
-
Type:
System.Collections.Generic::IEnumerable<T>^
The collection to compare to the current HashSet<T> object.
Return Value
Type: System::Booleantrue if the HashSet<T> object is a proper subset of other; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentNullException | other is null. |
An empty set is a proper subset of any other collection. Therefore, this method returns true if the collection represented by the current HashSet<T> object is empty unless the other parameter is also an empty set.
This method always returns false if Count is greater than or equal to the number of elements in other.
If the collection represented by other is a HashSet<T> collection with the same equality comparer as the current HashSet<T> object, then this method is an O(n) operation. Otherwise, this method is an O(n + m) operation, where n is Count and m is the number of elements in other.
The following example creates two disparate HashSet<T> objects and compares them to each other. In this example, lowNumbers is both a subset and a proper subset of allNumbers until allNumbers is modified, using the IntersectWith method, to contain only values that are present in both sets. Once allNumbers and lowNumbers are identical, lowNumbers is still a subset of allNumbers but is no longer a proper subset.
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1