Export (0) Print
Expand All

StringDictionary.ContainsKey Method

Determines if the StringDictionary contains a specific key.

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

abstract ContainsKey : 
        key:string -> bool  
override ContainsKey : 
        key:string -> bool


Type: System.String

The key to locate in the StringDictionary.

Return Value

Type: System.Boolean
true if the StringDictionary contains an entry with the specified key; otherwise, false.


The key is a null reference (Nothing in Visual Basic).

The key is handled in a case-insensitive manner; it is translated to lowercase before it is used.

This method is an O(1) operation.

Starting with the .NET Framework 2.0, this method uses the collection’s objects’ Equals and CompareTo methods on item to determine whether item exists. In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

The following code example searches for an element in a StringDictionary.

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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
© 2015 Microsoft