Determines whether the Hashtable contains a specific key.
- The key to locate in the Hashtable.
true if the Hashtable contains an element with the specified key; otherwise, false.
Type Reason ArgumentNullException key is null.
This method is an O(1) operation.
Starting with the .NET Framework 2.0, this method uses the collection’s objects’ object.Equals(object) and IComparable.CompareTo(object) methods on item to determine whether item exists. In the earlier versions of the .NET Framework, this determination was made by using the object.Equals(object) and IComparable.CompareTo(object) methods of the item parameter on the objects in the collection.