Iterating the Elements of a Collection

 
 // For sets and lists
   
   for (Iterator it=collection.iterator();
     it.hasNext(); ) {
     process(it.next());
   }
     
 // For keys of a map
   
   for (Iterator it=map.keySet().iterator();
     it.hasNext(); ) {
     process(it.next());
   }
     
 // For values of a map
 
   for (Iterator it=map.values().iterator();
     it.hasNext(); ) {
     process(it.next());
   }