StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POIterator.hasNext() goes nuts after remove() from collection
primarykey
Id
8065018
data
AcceptedAnswerId
8065090
AnswerCount
4
ClosedDate
CommentCount
6
CommunityOwnedDate
CreationDate
2011-11-09T12:27:15.927
FavoriteCount
1
LastActivityDate
2011-11-09T12:52:44.753
LastEditDate
LastEditorUserId
0
OwnerUserId
513342
ParentId
0
PostTypeId
1
Score
1
ViewCount
1973
LastEditorDisplayName
text
Body
The code is pretty simple: <pre><code> List lst1 = new ArrayList(){{add("1");}}; Iterator it = lst1.iterator(); System.out.println(it.hasNext()); it.next(); System.out.println(it.hasNext()); lst1.remove(0); System.out.println(it.hasNext()); </code></pre> I know that you should never remove from a collection while iterating through its iterator, please don't tell me that. Instead, please give me a sane explanation why would a remove() operation change the value returned by hasNext() from false to true: <pre><code>$ /usr/lib/jvm/sun-jdk-1.6/bin/java -version java version "1.6.0_26" Java(TM) SE Runtime Environment (build 1.6.0_26-b03) Java HotSpot(TM) Server VM (build 20.1-b02, mixed mode) true false true </code></pre> hasNext() API documentation clearly states that it should return true ONLY if there are more elements in the iterator, and calling next() returns an element. The output proves that it's not the case with SUN JDK 1.6 IBM JDK doesn't do that, hasNext returns false after remove() gets called: <pre><code>$ /usr/lib/jvm/ibm-jdk-bin-1.6/bin/java -version java version "1.6.0" Java(TM) SE Runtime Environment (build pxi3260sr9fp2-20110625_01(SR9 FP2)) IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Linux x86-32 jvmxi3260sr9-20110624_85526 (JIT enabled, AOT enabled) true false false </code></pre> Is there a bug in Sun/Oracle hasNext() method? Or, is there a bug in IBM hasNext() method? Or, should I just not bother with all that?
Tags
<java>
Title
Iterator.hasNext() goes nuts after remove() from collection
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USOleg Mikheev
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
3. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POIterator.hasNext() goes nuts after remove() from collection
 UserUserId
 USAlex K
 VoteTypeVoteTypeId
 VTFavorite
2. VO
 singulars
 PostPostId
 POIterator.hasNext() goes nuts after remove() from collection
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTDownMod
3. VO
 singulars
 PostPostId
 POIterator.hasNext() goes nuts after remove() from collection
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.