title: kotlin : what is difference between isNullOrEmpty and isNullOrBlank?
body: <p>I want check value of my EditText in android so I saw two function for my String value :</p>
  
  <blockquote>
    <p>user.isNullOrBlank()</p>
  </blockquote>
  
  <p>and </p>
  
  <blockquote>
    <p>user.isNullOrEmpty()</p>
  </blockquote>
  
  <p><strong>what is difference between them?</strong></p>