Item Property

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Gets or sets the value associated with the specified key.

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

public:
virtual property Object^ Item[Object^ key] {
	Object^ get (Object^ key) sealed;
	void set (Object^ key, Object^ value) sealed;
}

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 nullNothingnullptrunita null reference (Nothing in Visual Basic), and attempting to set it creates a new element using the specified key.

Implements

IDictionary..::..Item

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 Hashtable; for example, myCollection["myNonexistentKey"] = myValue. However, if the specified key already exists in the Hashtable, setting the Item property overwrites the old value. In contrast, the Add method does not modify existing elements.

A key cannot be nullNothingnullptrunita null reference (Nothing in Visual Basic), but a value can be. To distinguish between nullNothingnullptrunita null reference (Nothing in Visual Basic) that is returned because the specified key is not found and nullNothingnullptrunita null reference (Nothing in Visual Basic) that is returned because the value of the specified key is nullNothingnullptrunita 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.

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