I recommend, on principle, foregoing the enhanced for and using something like this instead: for(Iterator it=erator() it. To insert element to the specified index, you could write: let insertAt index newEl input // For each element, we generate a list of elements that should // replace the original one - either singleton list or two elements // for the specified index input > List.mapi (fun i el -> if i index then newEl el else el) > ncat. Right now you are removing the first occurrence - in future you might need to remove all matching occurrences, in which case you then have to rewrite the loop. For Each Str As String In listOfStrings If Str.Equals ('Pat') Then Dim index listOfStrings. You can't continue iteration after the remove unless you use the iterator's remove method. No you can not remove from a List that you are working on e.g.The collection could be, for example, a linked list (and in your case it is) whose remove method means searching for the object all over again, which search could have O(n) complexity.It is best to use an iterator and use it's remove method when searching for an object by iterating over a collection in order to remove it. I would treat this idiom similar to goto (or rather, labeled break/ continue): it may seem wrong at first, but when used wisely, it makes for a cleaner code. It may be best if you add a comment on the break, why it's absolutely necessary, etc, because if this code is later modified to continue iterating after a remove, it will fail. The iterator doesn't even get a chance to detect it. A successful exploit could allow the attacker to cause a stack overflow. Here, after the remove (which qualifies as concurrent modification), you break out of the loop. Solr 8.4 removed the params resource loader entirely, and only enables the. In addition to that, we also keep top pointer to represent the top of the stack. That's not the case here, so this shortcut is fine.Ī ConcurrentModificationException is checked and thrown by the iterator. A stack using a linked list is just a simple linked list with just restrictions that any element will be added and removed using push and pop respectively. To those who's saying that this will fail because you can't modify a collection in a foreach - this is true only if you want to keep iterating. If you need to do it with the 'remove' function, just use a simple loop once you have found the element described above. So yes, if you break out of the foreach after you remove, you'll be fine. Otherwise you'll get a ConcurrentModificationException, or in the more general case, undefined behavior. If you want to keep iterating after a remove, though, you need to use an iterator. HOWEVER, in this case it's fine since you break out of the loop once you remove. Others have mentioned the valid point that normally this is not how you remove an object from a collection.
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