title: Difference between null and empty ("") Java String
body: <p>What is the difference between <code>null</code> and the <code>""</code> (empty string)?</p>
  
  <p>I have written some simple code:</p>
  
  <pre><code>String a = "";
  String b = null;
  
  System.out.println(a == b); // false
  System.out.println(a.equals(b)); // false
  </code></pre>
  
  <p>Both statements return <code>false</code>. It seems, I am not able to find what is the actual difference between them.</p>