Dictionary<TKey,TValue>.KeyCollection.ICollection<TKey>.Contains Method
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Determines whether the ICollection<T> contains a specific value.
virtual bool System.Collections.Generic.ICollection<TKey>.Contains(TKey item) = System::Collections::Generic::ICollection<TKey>::Contains;
bool ICollection<TKey>.Contains (TKey item);
abstract member System.Collections.Generic.ICollection<TKey>.Contains : 'Key -> bool
override this.System.Collections.Generic.ICollection<TKey>.Contains : 'Key -> bool
Function Contains (item As TKey) As Boolean Implements ICollection(Of TKey).Contains
- item
- TKey
The object to locate in the ICollection<T>.
true
if item
is found in the ICollection<T>; otherwise, false
.
Implementations can vary in how they determine equality of objects; for example, List<T> uses Default, whereas, Dictionary<TKey,TValue> allows the user to specify the IComparer<T> implementation to use for comparing keys.
This method is an O(1) operation.
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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