I'm guessing your colleague felt that something where a response
of 0 things to operate on is not an error condition it is easier to
deal with a 0 entry list, for example:
public int getFooTotalValue() {
int fooTotal = 0;
List<Foo> fooList = getFooList();
for (Foo afoo : fooList ) {
fooTotal += afoo.getValue();
}
return fooTotal;
}
Handles the 0 length case without any checks. (Works nice for
totals, or "do an operation on a foo" loops, not so well for average,
or search for mean/median type loops.) It's nice in that it doesn't
make assumptions about what the List consuming code considers
an acceptable response. If you are prescient and know that every
possible consumer of the getFooList() result MUST have at least
one entry or it's an exceptional condition, I suppose you could go
with the NPE check, but I tend to feel that in isolation
if (!fooList.isEmpty()) {
}
gives me more information than
if (fooList != null) {
}
or the even more compact
if (fooList) {
}
As the isEmpty() case I know the list was set up correctly and I didn't
process fooList because there were no foo, where the !=null case could
be some initialization issue with foo (in the case of reading a file to
fill foo, I might want fooList = null for error condition of no/improperly
formatted file, empty list for read the file and found no foo.)
Dan
On Monday, August 4, 2014 3:51:38 PM UTC-4, sweety fx wrote:
>
> My colleague mentioned list is the better way of doing it. So that we
> don't face null pointer exceptions. since we check for list.isEmpty()
> But I wasn't sure, thats why I am checking.
>
> On Monday, August 4, 2014 3:42:35 PM UTC-4, Steve Gabrilowitz wrote:
>>
>> How would list.isEmpty() be better than object==null? If you never plan
>> on returning more than one object then it makes no sense to use a list.
>> On Aug 4, 2014 11:04 AM, "sweety fx" <fxsw...@gmail.com> wrote:
>>
>>> A method is supposed to return a object when called.
>>>
>>> Which is better to implement for the method:
>>> 1. Is it better to have the method return an object.
>>> 2. Or return List<Object> where the single object is added to the array
>>> list.
>>>
>>> because, we can check for list.isEmpty() which is better than
>>> object!=null. not sure which one is better.
>>>
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