title: How to do guard let statement in Kotlin like Swift?
body: <p>I want to write guard let statement in Kotlin like Swift.</p>
  
  <p>For example:</p>
  
  <pre class="lang-swift prettyprint-override"><code>guard let e = email.text , !e.isEmpty else { return }
  </code></pre>
  
  <p>Any advice or sample code? </p>