System.Collections.IDictionary.Contains Method

Determines whether the IDictionary object contains an element with the specified key.

Syntax

public bool Contains (object key)

Parameters

key
The key to locate in the IDictionary object.

Returns

true if the IDictionary contains an element with the key; otherwise, false.

Exceptions

TypeReason
ArgumentNullException key is null.

Remarks

Implementations can vary in whether they allow the key to be null.

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

Requirements

Namespace: System.Collections
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0