title: How can I check null and empty both in freemarker string?
body: <p>For example.
  String s can have these values like "value", "" or null.</p>
  
  <pre><code>&lt;#if str?? &amp;&amp; str?has_content&gt;
      ${str}
  &lt;/#if&gt;
  </code></pre>
  
  <p>Can I check ??(null) and ?has_content(empty not null) both value in freemarker if statement not using TemplateModel?</p>