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LinkedList.AddBefore Method (Generic LinkedListNode, T)

Adds a new node containing the specified value before the specified existing node in the LinkedList.

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

public LinkedListNode<T> AddBefore (
	LinkedListNode<T> node,
	T value
public LinkedListNode<T> AddBefore (
	LinkedListNode<T> node, 
	T value
public function AddBefore (
	node : LinkedListNode<T>, 
	value : T
) : LinkedListNode<T>
Not applicable.



The LinkedListNode before which to insert a new LinkedListNode containing value.


The value to add to the LinkedList.

Return Value

The new LinkedListNode containing value.

Exception typeCondition


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


node is not in the current LinkedList.

LinkedList accepts a null reference (Nothing in Visual Basic) as a valid Value for reference types and allows duplicate values.

This method is an O(1) operation.

The following code example and output demonstrate the AddBefore method. The code example finds the first node that has a particular value, and uses the AddBefore(Generic LinkedListNode,T) method overload to add two new nodes before it.

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

// Add 'quick' and 'brown' before 'fox':
sentence.AddBefore(current, "quick");
sentence.AddBefore(current, "brown");

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

.NET Compact Framework

Supported in: 2.0

XNA Framework

Supported in: 1.0