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XNode.CompareDocumentOrder Method

Compares two nodes to determine their relative XML document order.

Namespace:  System.Xml.Linq
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

public static int CompareDocumentOrder(
	XNode n1,
	XNode n2


Type: System.Xml.Linq.XNode
First XNode to compare.
Type: System.Xml.Linq.XNode
Second XNode to compare.

Return Value

Type: System.Int32
An int containing 0 if the nodes are equal; -1 if n1 is before n2; 1 if n1 is after n2.


The two nodes do not share a common ancestor.

The XContainer stores its child nodes as a singly-linked list of XNode objects. This means that the CompareDocumentOrder() method must traverse the ancestors of the two nodes being compared until it finds the common parent. Then it must traverse the list of the common parent’s child nodes to determine the order of the two nodes being compared. Therefore, using this method might affect your performance.

The following example uses this method.

XElement xmlTree = new XElement("Root",
    new XElement("Child1",
        new XElement("GrandChild1", 1),
        new XElement("GrandChild2", 2),
        new XElement("GrandChild3", 3)
    new XElement("Child2",
        new XElement("GrandChild4", 4),
        new XElement("GrandChild5", 5),
        new XElement("GrandChild6", 6)
XElement el1 = xmlTree.Descendants("GrandChild2").First();
XElement el2 = xmlTree.Descendants("GrandChild6").First();
if (XElement.CompareDocumentOrder(el1, el2) == 0)
    Console.WriteLine("Compared elements are the same element");
else if (XElement.CompareDocumentOrder(el1, el2) > 0)
    Console.WriteLine("el1 is after el2");
    Console.WriteLine("el1 is before el2");

This example produces the following output:

el1 is before el2

.NET Framework

Supported in: 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, 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.