How to: Find Sibling Nodes (XPath-LINQ to XML)

You might want to find all siblings of a node that have a specific name. The resulting collection might include the context node if the context node also has the specific name.

The XPath expression is:

../Book

Example

This example first finds a Book element, and then finds all sibling elements named Book. The resulting collection includes the context node.

This example uses the following XML document: Sample XML File: Books (LINQ to XML).

XDocument books = XDocument.Load("Books.xml");

XElement book = 
    books
    .Root
    .Elements("Book")
    .Skip(1)
    .First();

// LINQ to XML query
IEnumerable<XElement> list1 =
    book
    .Parent
    .Elements("Book");

// XPath expression
IEnumerable<XElement> list2 = book.XPathSelectElements("../Book");

if (list1.Count() == list2.Count() &&
        list1.Intersect(list2).Count() == list1.Count())
    Console.WriteLine("Results are identical");
else
    Console.WriteLine("Results differ");
foreach (XElement el in list1)
    Console.WriteLine(el);

Dim books As XDocument = XDocument.Load("Books.xml")
Dim book As XElement = books.Root.<Book>.Skip(1).First()

' LINQ to XML query
Dim list1 As IEnumerable(Of XElement) = book.Parent.<Book>

' XPath expression
Dim list2 As IEnumerable(Of XElement) = book.XPathSelectElements("../Book")

If list1.Count() = list2.Count() And _
        list1.Intersect(list2).Count() = list1.Count() Then
    Console.WriteLine("Results are identical")
Else
    Console.WriteLine("Results differ")
End If
For Each el As XElement In list1
    Console.WriteLine(el)
Next

This example produces the following output:

Results are identical
<Book id="bk101">
  <Author>Garghentini, Davide</Author>
  <Title>XML Developer's Guide</Title>
  <Genre>Computer</Genre>
  <Price>44.95</Price>
  <PublishDate>2000-10-01</PublishDate>
  <Description>An in-depth look at creating applications 
      with XML.</Description>
</Book>
<Book id="bk102">
  <Author>Garcia, Debra</Author>
  <Title>Midnight Rain</Title>
  <Genre>Fantasy</Genre>
  <Price>5.95</Price>
  <PublishDate>2000-12-16</PublishDate>
  <Description>A former architect battles corporate zombies, 
      an evil sorceress, and her own childhood to become queen 
      of the world.</Description>
</Book>

See Also

Concepts

LINQ to XML for XPath Users