Gets or sets the value associated with the specified key.
Assembly: mscorlib (in mscorlib.dll)
abstract Item : key:Object -> Object with get, set override Item : key:Object -> Object with get, set
- Type: System.Object
The key whose value to get or set.
Property ValueType: 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.
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 property to add new elements by setting the value of a key that does not exist in the Hashtable; for example, myCollection["myNonexistentKey"] = myValue. However, if the specified key already exists in the Hashtable, setting the property overwrites the old value. In contrast, the Add method does not modify existing elements.
A key cannot be a null reference (Nothing in Visual Basic), but a value can be. To distinguish between a null reference (Nothing in Visual Basic) that is returned because the specified key is not found and a null reference (Nothing in Visual Basic) that is returned because the value of the specified key is a null reference (Nothing in Visual Basic), use the Contains method or the ContainsKey method to determine if the key exists in the list.
Retrieving the value of this property is an O(1) operation; setting the property is also an O(1) operation.
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.