title: lambda expression for exists within list
body: <p>If I want to filter a list of objects against a specific id, I can do this:</p>
  
  <pre><code>list.Where(r =&gt; r.Id == idToCompare);   
  </code></pre>
  
  <p>What if, instead of a single <code>idToCompare</code>, I have a list of Ids to compare against?</p>
  
  <p>What is the syntax for comparing against a predefined list?  Something like:</p>
  
  <pre><code>int[] listofIds = GetListofIds();
  
  list.Where(r =&gt; r.Id "in listofIds");   
  </code></pre>