What is the most efficient way or best practice for null check when you use Split and FirstOrDefault methods together?

Question

I use Split and LastOrDefault methods together, I use this code block for null check. But it does not seems the most efficient way to me. Because I use lots of check and && operators. It seem a little ugly. Is there any way to accomplish this null-check in a better way? (I searched on web but couldn' t find related answers.)

Note : C# Language version 4.0

Here is my code :

    if (HttpContext.Current.Request.Url.AbsolutePath.Split('/') != null &&
        HttpContext.Current.Request.Url.AbsolutePath.Split('/').Length > 0 &&
        HttpContext.Current.Request.Url.AbsolutePath.Split('/').Last() != null &&
        HttpContext.Current.Request.Url.AbsolutePath.Split('/').Last().Split('.') != null &&
        HttpContext.Current.Request.Url.AbsolutePath.Split('/').Last().Split('.').Length > 0 &&
        HttpContext.Current.Request.Url.AbsolutePath.Split('/').Last().Split('.').First() != null)
    {
        pageName = HttpContext.Current.Request.Url.AbsolutePath.Split('/').LastOrDefault().Split('.').FirstOrDefault();
    }

Thanks for all answers.

Answer 1

The tests are all not needed:

First, don't run Split multiple times on the same data:

var splitSlashAbsPath = HttpContext.Current.Request.Url.AbsolutePath.Split('/');

The return array from Split can never be null

//    if (splitSlashAbsPath != null &&

the return array from Split can never be zero length

//        splitSlashAbsPath.Length > 0 &&

so the return from Last() can never be null

//        splitSlashAbsPath.Last() != null &&

Don't run split multiple times on the same data (and calling Last on an array doesn't make sense)

var splitDotAbsPath = splitSlashAbsPath[splitSlashAbsPath.Length-1].Split('.');

the return array from Split can never be null

//        splitDotAbsPath != null &&

the return array from Split can never be zero length

//        splitDotAbsPath.Length > 0 &&

so, the First() from Split can never be null

//        splitDotAbsPath.First() != null)
//    {

since you can call Last, calling LastOrDefault makes no sense same for FirstOrDefault

//        pageName = splitDotAbsPath.FirstOrDefault();

Calling First on an array also doesn't make sense

pageName = splitDotAbsPath[0];

//    }

So, in summary you have:

var splitSlashAbsPath = HttpContext.Current.Request.Url.AbsolutePath.Split('/');
var splitDotAbsPath = splitSlashAbsPath[splitSlashAbsPath.Length-1].Split('.');
pageName = splitDotAbsPath[0];

However, in general, using Split for just getting one element is very inefficient, so this would be better:

var path = HttpContext.Current.Request.Url.AbsolutePath;
var pastSlashPos = path.LastIndexOf('/') + 1;
var countUntilDot = path.IndexOf('.', pastSlashPos);
countUntilDot = (countUntilDot >= 0 ? countUntilDot : path.Length) - pastSlashPos;
pageName = path.Substring(pastSlashPos, countUntilDot);