Iterator order of List or Set in java

Question

Is the iteration order of a collection iterator fixed?

Is the iteration order of the iterator the same as the storage order of its collection (List and Set)?

Does this answer your question? [Java Set retain order?](https://stackoverflow.com/questions/10752753/java-set-retain-order) — sanjeevRm, Jul 12 '21 at 06:49

score 0 · Answer 1 · answered Jul 12 '21 at 06:47

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List are ordered collections but sets aren't, so both questions are yes in case of lists and no in case of sets. You can view it in java documentation

https://docs.oracle.com/javase/8/docs/api/java/util/List.html

An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list.

https://docs.oracle.com/javase/8/docs/api/java/util/Set.html

Iterator iterator() Returns an iterator over the elements in this set. The elements are returned in no particular order (unless this set is an instance of some class that provides a guarantee).

answered Jul 12 '21 at 06:47

JArgente

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Is the sequence of each iteration of a Set iterator the same for repeated iterations? – Jeremy Xu Jul 12 '21 at 07:16
This is something that Java doesn't assure so it could be or not – JArgente Jul 12 '21 at 07:24
A set iterator repeats traversal,the output is not guaranteed to be the same every time? – Jeremy Xu Jul 12 '21 at 08:01

Iterator order of List or Set in java

1 Answers1