title: How to join array in pipe
body: <p>I wish to join the result from a pipe.</p>
  
  <p>I tried using <code>-join</code></p>
  
  <pre><code>PS&gt; type .\bleh.log | where { $_ -match "foo"} | select -uniq | $_ -join ','
  </code></pre>
  
  <p>But that give me this error :/</p>
  
  <blockquote>
    <p>Expressions are only allowed as the first element of a pipeline.</p>
  </blockquote>