Question

I got the following code :

foreach (string file in Directory.GetFiles(generationDir, "*.xaml")
{
    File.Delete(file);
}

foreach (string file in Directory.GetFiles(generationDir, "*.cs")
{
    File.Delete(file);
}

I’d like to merge these 2 foreach in a single loop ? Is that possible ?
I’m not comfortable with lambda expression so got a hard time here…

Answer 1

foreach (var file in 
         Directory.GetFiles(generationDir, "*.*")
                  .Where(item => item.EndsWith(".xaml") || item.EndsWith(".cs")))
                   {
                       File.Delete(file);
                   }

For those who like ForEach() “sequence operator fake” 🙂
(Please be aware of “foreach” vs “ForEach” before usign it)

Directory.GetFiles(generationDir, "*.*")
         .Where(item => item.EndsWith(".xaml") || item.EndsWith(".cs"))
         .ToList()
         .ForEach(item => File.Delete(item))

If you are usign .NET Framework v4 you can use more efficient Directory.EnumerateFiles() method:

The EnumerateFiles and GetFiles methods differ as follows: When you
use EnumerateFiles, you can start enumerating the collection of names
before the whole collection is returned; when you use GetFiles, you
must wait for the whole array of names to be returned before you can
access the array. Therefore, when you are working with many files and
directories, EnumerateFiles can be more efficient.

The returned collection is not cached; each call to the GetEnumerator
on the collection will start a new enumeration.