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How to find a single descendant using the Descendants method (LINQ to XML)

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You can use the Descendants axis method to find a single uniquely-named descendant element. This technique is especially useful when you want to find a particular descendant with a specific name, and may be faster and easier to use than navigating the XML tree.

Example: Use XContainer.Descendants to find a single uniquely-named descendant element

This example uses the First standard query operator.

XElement root = XElement.Parse(@"<Root>
  <Child1>
    <GrandChild1>GC1 Value</GrandChild1>
  </Child1>
  <Child2>
    <GrandChild2>GC2 Value</GrandChild2>
  </Child2>
  <Child3>
    <GrandChild3>GC3 Value</GrandChild3>
  </Child3>
  <Child4>
    <GrandChild4>GC4 Value</GrandChild4>
  </Child4>
</Root>");
string grandChild3 = (string)
    (from el in root.Descendants("GrandChild3")
    select el).First();
Console.WriteLine(grandChild3);

Dim root As XElement = _
    <Root>
        <Child1>
            <GrandChild1>GC1 Value</GrandChild1>
        </Child1>
        <Child2>
            <GrandChild2>GC2 Value</GrandChild2>
        </Child2>
        <Child3>
            <GrandChild3>GC3 Value</GrandChild3>
        </Child3>
        <Child4>
            <GrandChild4>GC4 Value</GrandChild4>
        </Child4>
    </Root>
Dim grandChild3 As String = _
    (From el In root...<GrandChild3> _
    Select el).First()
Console.WriteLine(grandChild3)

This example produces the following output:

GC3 Value

Example: Find when the XML is in a namespace

The following example does the same as the previous one, but for XML that's in a namespace. For more information, see Namespaces overview.

XElement root = XElement.Parse(@"<aw:Root xmlns:aw='http://www.adventure-works.com'>
  <aw:Child1>
    <aw:GrandChild1>GC1 Value</aw:GrandChild1>
  </aw:Child1>
  <aw:Child2>
    <aw:GrandChild2>GC2 Value</aw:GrandChild2>
  </aw:Child2>
  <aw:Child3>
    <aw:GrandChild3>GC3 Value</aw:GrandChild3>
  </aw:Child3>
  <aw:Child4>
    <aw:GrandChild4>GC4 Value</aw:GrandChild4>
  </aw:Child4>
</aw:Root>");
XNamespace aw = "http://www.adventure-works.com";
string grandChild3 = (string)
    (from el in root.Descendants(aw + "GrandChild3")
     select el).First();
Console.WriteLine(grandChild3);

Imports <xmlns:aw='http://www.adventure-works.com'>

Module Module1
    Sub Main()
        Dim root As XElement = _
            <aw:Root>
                <aw:Child1>
                    <aw:GrandChild1>GC1 Value</aw:GrandChild1>
                </aw:Child1>
                <aw:Child2>
                    <aw:GrandChild2>GC2 Value</aw:GrandChild2>
                </aw:Child2>
                <aw:Child3>
                    <aw:GrandChild3>GC3 Value</aw:GrandChild3>
                </aw:Child3>
                <aw:Child4>
                    <aw:GrandChild4>GC4 Value</aw:GrandChild4>
                </aw:Child4>
            </aw:Root>
        Dim grandChild3 As String = _
            (From el In root...<aw:GrandChild3> _
            Select el).First()
        Console.WriteLine(grandChild3)
    End Sub
End Module

This example produces the following output:

GC3 Value