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Collection.Item Property (String)

Returns a specific element of a Collection object either by position or by key. Read-only.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public Object this[
	string Key
] { get; }


Type: System.String

A unique String expression that specifies a key string that can be used, instead of a positional index, to access an element of the collection. Key must correspond to the Key argument specified when the element was added to the collection.

Property Value

Type: System.Object
Returns a specific element of a Collection object either by position or by key. Read-only.

If Index is of type Object, the Item property attempts to treat it as a String, Char, Char array, or integer value. If Item cannot convert Index to String or Integer, it throws an ArgumentException exception.

The Item property is the default property for a collection. Therefore, the following lines of code are equivalent.


The following example uses the Item property to retrieve a reference to an object in a collection. It creates birthdays as a Collection object and then retrieves the object representing Bill's birthday, using the key "Bill" as the Index argument.

Dim birthdays As New Collection()
birthdays.Add(New DateTime(2001, 1, 12), "Bill")
birthdays.Add(New DateTime(2001, 1, 13), "Joe")
birthdays.Add(New DateTime(2001, 1, 14), "Mike")
birthdays.Add(New DateTime(2001, 1, 15), "Pete")


Dim aBirthday As DateTime
aBirthday = birthdays.Item("Bill")
aBirthday = birthdays("Bill")

Note that the first call explicitly specifies the Item property, but the second does not. Both calls work because the Item property is the default property for a Collection object.

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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