title: C# Modify objects in a list of objects
body: <p>I have a list of objects returning from a function.
  How I can traverse the list and modify some objects, like append a specific string
  to all cells (integers) of a specific column? I could also add 2 more string columns: sid_s and num_s if its easier...</p>
  
  <pre><code>List&lt;object&gt; data = (from q in dc.Queries
                                   join ss in dc.Sites on q.SiteId equals ss.Siteid
                                   where q.CTid == 100
                                   select new
                                   {
                                       s.id, //integer to string
                                       q.name,
                                       q.num
                                   }).ToList&lt;object&gt;();
  </code></pre>
  
  <p>Here is my list:</p>
  
  <blockquote>
    <p>sid | name | num </p>
    
    <p>100 | a    | 2001 </p>
    
    <p>101 | b    | 2002 </p>
  </blockquote>
  
  <p>I want to change it to:</p>
  
  <blockquote>
    <p>sid | name | num              </p>
    
    <p>100qq | a    | 2001zz                      </p>
    
    <p>101qq | b    | 2002zz                      </p>
  </blockquote>
  
  <p>OR           </p>
  
  <blockquote>
    <p>sid | name | num | sid_s | num_s</p>
    
    <p>100 | a    | 2001| 100qq |2001zz</p>
    
    <p>101 | b    | 2002| 101qq |2002zz</p>
  </blockquote>