Avoid Repeating Oneself When Doing A Select From IEnumerable

Question

I have an IEumerable<XElement> called foo.

I have this code

foo.Select(x => new
        {
            bars = x.Descendants(namespace + "bar") != null 
                ? x.Descendants(namespace + "bar").Select(z => z.Value).ToArray() 
                : new string[0]
        })
        .ToArray();

How can I write this a little neater? I really don't want to repeat this part

x.Descendants(namespace + "bar")

Answer 1

Using an additional Select:

foo.Select(x => x.Descendants(namespace + "bar"))
   .Select(x => new
            {
                bars = x != null ? x.Select(z => z.Value).ToArray() : new string[0]
            })
            .ToArray();

Or:

foo.Select(x =>
               {
                   var elements = x.Descendants(namespace + "bar");
                   return new
                   {
                      bars = elements != null ? elements.Select(z => z.Value).ToArray() : new string[0]
                   }
                })
            .ToArray();

BTW, I don't think Descendants will return null.You should probably check whether there are any elements using Any method.

 bars = x.Any() ? x.Select(z => z.Value).ToArray() : new string[0]