Csharp/C Sharp/XML LINQ/ReplaceAll

Using ReplaceAll to Change an Element"s Subtree

 
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XElement firstParticipant;
        XDocument xDocument = new XDocument(
          new XElement("Books", firstParticipant =
            new XElement("Book",
              new XAttribute("type", "Author"),
              new XElement("FirstName", "J"),
              new XElement("LastName", "R"))));
        Console.WriteLine(xDocument);
        firstParticipant.ReplaceAll(
             new XElement("FirstName", "C"),
             new XElement("LastName", "D"));
        Console.WriteLine(xDocument);
    }
}