title: class cast exception java
body: <pre><code>interface Foo { 
  
  }
  class Beta implements Foo { 
  
  }
  public class Main extends Beta{
      public static void main(String[] args) {
          Beta x = new Beta();
          Foo f= (Main)x;
          }
  }
  </code></pre>
  
  <p>output <code>java.lang.ClassCastException</code>.
  Why it is happening please xplain?</p>