title: Do redundant expressions, directives and qualifiers impact performance?
body: <p>I'm working with somebody else's code right now and ReSharper is giving me a lot of warnings about redundant code, such as:</p>
  
  <ul>
  <li>Unused directives</li>
  <li>Array creation expressions (<code>new string[]{xxx,xxx,xxx}</code> instead of <code>{xxx,xxx,xxx}</code>)</li>
  <li>Explicit delegate creation (<code>new EventHandler(xxx)</code> instead of <code>xxx</code>)</li>
  <li>Qualifiers (<code>System.Windows.Forms.Form</code> instead of <code>Form</code> when directives are used)</li>
  </ul>
  
  <p>There is a lot of code to work with, so I'm not sure if it's worth going through it all and removing all redundant code.</p>
  
  <p>With that in mind, I wanted to ask if these are warnings that are only there to improve code style (for aesthetics) or do those pieces of code actually perform extra operations and impact performance a little?</p>