title: List vs Dictionary (Hashtable)
body: <p>This may be a silly question but I am reading about that <code>Hashtables</code> and <code>Dictionaries</code> are faster than a list because they index the items with keys.</p>
  
  <p>I know a <code>List</code> or <code>Array</code> is for elements without values, and a <code>Dictionary</code> is for elements with values. So I would think that it maybe be smart to have a <code>Dictionary</code> with the value that you need as a key and the value equal in all of them?</p>
  
  <p><strong>Update</strong>:</p>
  
  <p>Based on the comments what I think I need is a <code>HashSet</code>. This <a href="https://stackoverflow.com/questions/150750/hashset-vs-list-performance">question</a> talks about their performance.</p>