Windows apps
Collapse the table of content
Expand the table of content
Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

SortedDictionary<TKey, TValue>::ContainsKey Method (TKey)

 

Determines whether the SortedDictionary<TKey, TValue> contains an element with the specified key.

Namespace:   System.Collections.Generic
Assembly:  System (in System.dll)

public:
virtual bool ContainsKey(
	TKey key
) sealed

Parameters

key
Type: TKey

The key to locate in the SortedDictionary<TKey, TValue>.

Return Value

Type: System::Boolean

true 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.

No code example is currently available or this language may not be supported.
No code example is currently available or this language may not be supported.
No code example is currently available or this language may not be supported.

Universal Windows Platform
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
Return to top
Show:
© 2017 Microsoft