title: find out the words with substring in LINQ
body: <p>I have an array of words</p>
  
  <pre><code> string[] words = { "believe", "relief", "receipt", "field" };
  </code></pre>
  
  <p>How to find out the words with the substring "ei" using linq</p>
  
  <pre><code>IEnumerable&lt;string&gt; iswordlist = from word in words where words.All(a =&gt; a.Contains("ei"))
                                               select word;
              foreach (var i in iswordlist)
              {
                  txtlinq.Text = txtlinq.Text + i.ToString();
              }
  </code></pre>
  
  <p>I tried the above but got no result. Can anyone help me on this?</p>