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LinkedList<T>.AddFirst Method (LinkedListNode<T>)

Adds the specified new node at the start of the LinkedList<T>.

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

public void AddFirst(
	LinkedListNode<T> node
)

Parameters

node
Type: System.Collections.Generic.LinkedListNode<T>
The new LinkedListNode<T> to add at the start of the LinkedList<T>.

ExceptionCondition
ArgumentNullException

node is null.

InvalidOperationException

node belongs to another LinkedList<T>.

LinkedList<T> accepts null as a valid Value for reference types and allows duplicate values.

If the LinkedList<T> is empty, the new node becomes the First and the Last.

This method is an O(1) operation.

The following code example and output demonstrate the AddFirst method. The code example removes the last node in a linked list of strings, adds a new node to the end of the list, marks that node, removes it, and finally uses the AddFirst(LinkedListNode<T>) method overload to insert the node at the beginning of the list.

This code and output are part of a larger example provided for the LinkedList<T> class.


// Move the last node to be the first node.
mark1 = sentence.Last;
sentence.RemoveLast();
sentence.AddFirst(mark1);


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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