SortedDictionary(Of TKey, TValue).ContainsKey Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Determines whether the SortedDictionary(Of 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(Of TKey, TValue).
Return Value
Type: System.Booleantrue if the SortedDictionary(Of TKey, TValue) contains an element with the specified key; otherwise, false.
Implements
IDictionary(Of TKey, TValue).ContainsKey(TKey)| Exception | Condition |
|---|---|
| ArgumentNullException | key is Nothing. |
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(Of TKey, TValue) class.