Why I need to call setChanged before I notify the observers?
<p>I learned about <a href="http://docs.oracle.com/javase/1.4.2/docs/api/java/util/Observable.html#setChanged%28%29" rel="nofollow">Observable</a> class in java. and there is somthing that I didnt understood. before notify the observers (notifyObservers()) I must call the setChanged method. I understood that behind the scenes there is a condition inside notifyObservers method. But for what purpose this condition needed?</p>
