find the 1st occurrence without using loop

Question

I have an object class named Store which has an attribute "year":

public class Store{
     public int year;
     ...
}

Then, in another class I got a list of Store :

List<Store> stores = getAllStores();

I would like to get from the list the 1st occurrence of store whose year is 2002 without using for loop or while loop. Is it possible?

You should consider using linq where statement and then doing first or default — Ehsan, Jun 28 '13 at 06:45
You need to You `Collection`. Detail can be found [here][1] [1]: http://stackoverflow.com/questions/4404084/find-if-a-value-exists-in-arraylist — twid, Jun 28 '13 at 06:46
Depending on how Store's `equals` method works, you could use `List#indexOf` to find the first occurrence of a particular store. If the `equals` method is based on just the year, it should work (though it still uses a loop under the covers. — Aurand, Jun 28 '13 at 06:47
If you are the one writing the store class consider adding additional information to your object to store the first one of each year for example. Why can't you use a loop ? — HpTerm, Jun 28 '13 at 06:47
@basar if not syntax, then the concern would be to mess with us ;p — necromancer, Jun 28 '13 at 06:50
If you only mind the first year, why not using a Map and use the year as the key? — clement, Jun 28 '13 at 06:48

score 5 · Answer 1 · answered Jun 28 '13 at 06:49

5

to iterate is human, to recurse divine

answered Jun 28 '13 at 06:49

necromancer

23,916
22
68
115

1

+1 @Thihara for allowing yourself to smile on StackOverflow which is not allowed. Is it ? ;-) – HpTerm Jun 28 '13 at 06:52
@HpTerm and @Thihara thanks, it was easier than writing out a custom `ListIterator < Store >` implementation that implemented `next()` recursively – necromancer Jun 28 '13 at 06:53
1

you made my day also +1 for the obvious. – basar Jun 28 '13 at 06:54
Asking myself up to which number of upvotes you will go with such an answer. – HpTerm Jun 28 '13 at 06:56
@HpTerm ask not how many upvotes one's answer gets, ask whether it will be accepted. (ps: on the karma account, mine is the only upvote on the question. just saying... ;) – necromancer Jun 28 '13 at 06:59
@Thihara nice contribution yourself ;) – necromancer Jun 28 '13 at 07:05

score 0 · Answer 2 · answered Jun 28 '13 at 06:54

I think you wanted something like ReturnTop where year is 2002, which there are 2 conditions underlying.

Is the objects sorted before added into the list? Is there any patterns that uniquely identify 2002 or have you consider hashmap? Have you considered a stack or a queue where 2002 is the first or the last added?

find the 1st occurrence without using loop

2 Answers2