Question

I have a class Agent with a property Id

Given a collection of Agents I need to check if any of them have duplicate Ids.

I am currently doing this with a hash table but am trying to get Linq-ified, what’s a good way of doing this?

Answer 1

Similar to Y Low’s approach,

Edited:

 var duplicates = agents.GroupBy(a => a.ID).Where(a=>a.Count() > 1);   foreach (var agent in duplicates)  {          Console.WriteLine(agent.Key.ToString());  }