Check List for duplications with optional words to exclude

Question

I have a method as below. Method return either false/true either when list contains duplicates or not. I would like to extend my method to say for instance (optional) that i

Answer 1

Instead of making your method more complicated, you should open it more to combine it with others:

public static class MyLinqMethods
{
  public static bool HasDuplicates(this IEnumerable sequence)
  {
      return sequence.GroupBy(n => n).Any(c => c.Count() > 1);
  }
}

Now you can use it with Linq:

var original = new[] { string.Empty, "Hello", "World", string.Empty };

var duplicatesInOriginal = original.HasDuplicates();

var duplicatesIfStringEmptyIsIgnored = original.Where(o => o != string.Empty).HasDuplicates();