JOIN XML Documents on Value using LINQ

I need to join two XML documents using LINQ and I'm not sure where to start. I need to join Document 1 and Document 2 on the values of the EmailAddre开发者_运维问答ss nodes and create a final output document that contains the value of the status field from Document 2.

Can anyone help?

Document 1

Document 2

Final Document

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The first step is to create a dictionary to map the emails to their status values. Next, select all the email address elements from the first document and set their attributes based on the dictionary.

var dict = secondDoc.Descendants("EmailAddress")
                    .ToDictionary(e => e.Value, e => e.Attribute("status").Value);

var emails = firstDoc.Descendants()
                     .Where(e => e.Name.LocalName.StartsWith("EmailAddress") 
                       && Char.IsDigit(e.Name.LocalName[e.Name.LocalName.Length - 1]));

foreach (var email in emails)
{
    string attribute;
    if (dict.TryGetValue(email.Value, out attribute))
    {
        email.SetAttributeValue("status", attribute);
    }
}

This approach will directly update firstDoc; it doesn't create a new XElement or XDocument. I added the Char.IsDigit check to avoid incorrectly matching an EmailAddress field that doesn't end with a number, should one exist. If you're certain that will never be the case then you can remove that check from the query.