title: Why String.valueOf(null) is causing null pointer exception?
body: <p>Why String.valueOf(null) is causing null pointer exception? Where the expected behaviour is to return "null" string. </p>
  
  <pre><code>String x = null;
      System.out.println(String.valueOf(x));
  </code></pre>
  
  <p>This give a "null" string. but </p>
  
  <pre><code>System.out.println(String.valueOf(null));
  </code></pre>
  
  <p>will cause null pointer exception.</p>