Question

In Java 5 and above you have the foreach loop, which works magically on anything that implements Iterable:

for (Object o : list) {   doStuff(o); } 

However, Enumerable still does not implement Iterable, meaning that to iterate over an Enumeration you must do the following:

for(; e.hasMoreElements() ;) {   doStuff(e.nextElement()); } 

Does anyone know if there is a reason why Enumeration still does not implement Iterable?

Edit: As a clarification, I’m not talking about the language concept of an enum, I’m talking a Java-specific class in the Java API called ‘Enumeration‘.

Answer 1

Enumeration hasn’t been modified to support Iterable because it’s an interface not a concrete class (like Vector, which was modifed to support the Collections interface).

If Enumeration was changed to support Iterable it would break a bunch of people’s code.