NameValueCollection.Item Property (String)
Gets or sets the entry with the specified key in the NameValueCollection.
Assembly: System (in System.dll)
The collection is read-only and the operation attempts to modify the collection.
This property provides the ability to access a specific element in the collection by using the following syntax: myCollection[name].
If the specified key already exists in the collection, setting this property overwrites the existing list of values with the specified value. To append the new value to the existing list of values, use the Add method.
If the specified key does not exist in the collection, setting this property creates a new entry using the specified key and the specified value.
This property returns null in the following cases: 1) if the specified key is not found; and 2) if the specified key is found and its associated value is null. This property does not distinguish between the two cases.
The C# language uses the this keyword to define the indexers instead of implementing the Item property. Visual Basic implements Item as a default property, which provides the same indexing functionality.
Retrieving or setting the values associated with the specified key is an O(n) operation, where n is the number of values.