title: update a List<Object> with LINQ
body: <p>I am trying to add a <code>SELECT ALL</code> functionality to my grid with LINQ, but I get a compilation error.</p>
  
  <pre><code>List&lt;Person_&gt; PeopleUpdated = People.ToList().ForEach(a =&gt; a.SELECTED = true).ToList();
  </code></pre>
  
  <p>It says </p>
  
  <blockquote>
    <p>Cannot implicitly convert type 'void' to
    'System.Collections.Generic.List &lt;
    LogoSapHrIntegration.frmXmlUpload.Person_>'</p>
  </blockquote>
  
  <p>what am I doing wrong?</p>