title: PowerShell and the -contains operator
body: <p>Consider the following snippet:</p>
  <pre><code>&quot;12-18&quot; -Contains &quot;-&quot;
  </code></pre>
  <p>You’d think this evaluates to <code>true</code>, but it doesn't. This will evaluate to <code>false</code> instead. I’m not sure why this happens, but it does.</p>
  <p>To avoid this, you can use this instead:</p>
  <pre><code>&quot;12-18&quot;.Contains(&quot;-&quot;)
  </code></pre>
  <p>Now the expression will evaluate to true.</p>
  <p>Why does the first code snippet behave like that? Is there something special about <code>-</code> that doesn't play nicely with <code>-Contains</code>? <a href="http://technet.microsoft.com/en-us/library/hh847759.aspx" rel="noreferrer">The documentation</a> doesn't mention anything about it.</p>