Comments on: C#: How to check for duplicates

By: MattE303

MattE303 — Fri, 14 Oct 2011 17:36:56 +0000

very useful Torleif, thanks!

By: Torleif

Torleif — Wed, 11 May 2011 20:12:56 +0000

Thanks for the tip! Added the explanation.

On the matter of your simplification, the code might look simpler to you, but it would make it less efficient again since it would have to go through all the subjects first to do the filtering. The code in my post returns immediately if it finds a duplicate.

By: mtazva

mtazva — Wed, 11 May 2011 15:06:54 +0000

It might help for those who find this post to note why the first implementation is bad, so that they can identify similar issues in other scenarios.

Also, you could simplify the for loop in your solution using a LINQ statement as follows:

return subjects.Where(s => !set.Add(s)).Any();