DictionaryBase.IDictionary.Contains Method (Object)
.NET Framework (current version)
Determines whether the DictionaryBase contains a specific key.
Assembly: mscorlib (in mscorlib.dll)
private abstract Contains : key:Object -> bool private override Contains : key:Object -> bool
Parameters
- key
-
Type:
System.Object
The key to locate in the DictionaryBase.
Return Value
Type: System.Booleantrue if the DictionaryBase contains an element with the specified key; otherwise, false.
Implements
IDictionary.Contains(Object)| Exception | Condition |
|---|---|
| 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’ Equals and CompareTo methods on key 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 key parameter on the objects in the collection.
Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Available since 10
.NET Framework
Available since 1.1
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