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DictionaryBase.IDictionary.Item Property

Gets or sets the value associated with the specified key.

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

private abstract Item : 
        key:Object -> Object with get, set 
private override Item : 
        key:Object -> Object with get, set

Parameters

key
Type: System.Object

The key whose value to get or set.

Property Value

Type: System.Object
The value associated with the specified key. If the specified key is not found, attempting to get it returns a null reference (Nothing in Visual Basic), and attempting to set it creates a new element using the specified key.

Implements

IDictionary.Item

ExceptionCondition
ArgumentNullException

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

NotSupportedException

The property is set and the DictionaryBase is read-only.

-or-

The property is set, key does not exist in the collection, and the DictionaryBase has a fixed size.

This property provides the ability to access a specific element in the collection by using the following syntax: myCollection[key].

You can also use the Item property to add new elements by setting the value of a key that does not exist in the DictionaryBase; for example, myCollection["myNonexistentKey"] = myValue. However, if the specified key already exists in the DictionaryBase, setting the Item property overwrites the old value. In contrast, the Add method does not modify existing elements.

Retrieving the value of this property is an O(1) operation; setting the property is also an O(1) operation.

The following code example implements the DictionaryBase class and uses that implementation to create a dictionary of String keys and values that have a Length of 5 characters or less.

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
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