title: Do Java's regular arrays have built in methods?
body: <p>I know that a regular Java array <code>int[] arr = new int[5];</code> lives in the heap and therefore it is considered as an object. Although it is considered as an object it is different from other Java obects because it cannot do everything that other Java objects can.</p>
  
  <p>One of the books I read about Java says, that </p>
  
  <blockquote>
    <p>"Even though an array is an object, it lives in its own special world
    and you can't invoke any methods on it, although you can access its
    one and only instance variable, length"</p>
  </blockquote>
  
  <p>This book is based on java 5.0. </p>
  
  <p>I am using netbeans as an IDE, and strangely enough I noticed that some methods can be invoked on the array object "arr".</p>
  
  <pre><code>arr.equals()
  arr.clone()
  arr.getClass() --&gt; this gives class [I, and I don't know what it means
  </code></pre>
  
  <p>Was the book wrong, or were these methods introduced in recent versions? And what is <code>class [I</code> </p>