title: java.util.UUID.randomUUID().toString() length
body: <p>Does java.util.UUID.randomUUID().toString() length always equal to 36?</p>
  
  <p>I was not able to find info on that. <a href="http://docs.oracle.com/javase/7/docs/api/java/util/UUID.html" rel="noreferrer">Here</a> it is said only the following: </p>
  
  <blockquote>
    <p>public static UUID randomUUID()
    Static factory to retrieve a type 4 (pseudo randomly generated) UUID. The UUID is generated using a cryptographically strong pseudo random number generator.
    Returns:
    A randomly generated UUID</p>
  </blockquote>
  
  <p>And that <code>type 4</code> tells me nothing. I do not know what type 4 means in the case.</p>