SortedDictionary<TKey, TValue>::ContainsKey Method (TKey)
Determines whether the SortedDictionary<TKey, TValue> contains an element with the specified key.
Assembly: System (in System.dll)
Parameters
- key
-
Type:
TKey
The key to locate in the SortedDictionary<TKey, TValue>.
Return Value
Type: System::Booleantrue if the SortedDictionary<TKey, TValue> contains an element with the specified key; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentNullException | key is null. |
This method is an O(log n) operation.
The following code example shows how to use the ContainsKey method to test whether a key exists prior to calling the Add method. It also shows how to use the TryGetValue method to retrieve values, which is an efficient way to retrieve values when a program frequently tries keys that are not in the dictionary. Finally, it shows the least efficient way to test whether keys exist, by using the Item property (the indexer in C#).
This code example is part of a larger example provided for the SortedDictionary<TKey, TValue> class.
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1