Why enhanced for loop is not performing the null checking

Question

Why the enhanced for loop is not performing null checking before iterating over the collection.

Answer 1

If you mean that this would go bang:

int[] array = null;
for (int x : array) {
}

... then I think it's entirely proper for that to throw a NullPointerException. The alternative would be for it to silently swallow the null, and treat that as equivalent to an empty array. That's not the approach Java takes anywhere else - why should this be different? It would make the language inconsistent.

The one place I wish there were more handling (but explicit handling) is switching on an enum - it would be nice to be able to provide a case for null, to avoid checking for that one special value beforehand. But that's a very different construct, which is specifically trying to take different actions for different values.

Answer 2

I kind of afraid to assert against Jon Skeet... :| ... But what a hell... what do you think about this scenario?:

`

findMoney(List<Places> places){
   int money = 0;
   for(Place place : places){
   money += searchWithCare(place);
   }
return money;
}

`

If I ask some client to tell me where to look and he tells me nothing. Do you think is better here to throw a NullPointerException? May be manage the call to this method so if parameter is null not call it?.... I think that return 0 is a consistent response because no error is here. I believe Exceptions are made to manage flow of code and I dont see why should I change the flow in this kind of situation. Return a cero or even a null could be a good response, couldnt it be?

So what about this solution? `

findMoney(List<Places> places){
   int money = 0;
   for(Place place : places == null ?Collections.<Place>emptyList():places){
   money += searchWithCare(place);
   }
return money;
}

`