title: Is toString() defined to return this for a java.lang.String?
body: <p>Consider</p>
  
  <pre><code>String foo = s.toString();
  </code></pre>
  
  <p>for a non-<code>null</code> <code>java.lang.String</code> instance <code>s</code>.</p>
  
  <p>Is this defined to return itself, or is it up to a particular Java implementation? Out of interest is a "deep copy" taken?</p>
  
  <p>Examining my source code of my JDK affirms that <code>s</code> is returned, but does the JLS insist on that? I've been brought up to regard <code>toString()</code> as an arbitrary serialisation, perhaps representative of the object, but not necessarily so. For example, it's entirely plausible (in my opinion at least) that an implementation could surround the string in quotation characters.</p>