Implement array list#1789
Conversation
mateacademy-ai-mentor
left a comment
mateacademy-ai-mentor
left a comment
There was a problem hiding this comment.
Review Summary
This code has critical issues that must be fixed before approval. First, there's a critical bug in the add(T value, int index) method where a redundant System.arraycopy(elements, 0, elements, 0, size - index) call copies the array to itself, corrupting all data - this line must be removed entirely as the second arraycopy handles the shifting correctly. Second, the indexOf() method uses Objects.equals() which is explicitly forbidden by the checklist - replace this with manual null-safe comparison using == or calling equals() on the parameter. Third, remove empty lines between field declarations (INIT_CAPACITY, elements, size) to comply with style guidelines [CHECKLIST ITEM #1]. The core ArrayList logic is sound, but these issues must be addressed before approval.
✨ Please rate this review in the Platform's notification center1. I will be grateful for your feedback! ✨
Important
Fix the issues, commit the changes, and then re-request my review using the Re-request review button2 in the Reviewers tab.
Tip
If you have any comments about this review, please leave a message in the Add a comment section below and mention me with the @mateacademy-ai-mentor tag3.
I will read your message during my next review of your pull request. Please do not reply directly to my comments, as that feature is not supported yet.
Caution
Do not close the pull request until the review is complete. Closing it early can lead to unexpected behavior and disrupt the review process.
Footnotes
| private int size = 0; | ||
|
|
There was a problem hiding this comment.
CHECKLIST VIOLATION #1: Empty line between field declarations and method implementation. Don't begin method implementation with an empty line.
| private int indexOf(T element) { | ||
| for (int i = 0; i < size; i++) { | ||
| if (Objects.equals(element, elements[i])) { |
There was a problem hiding this comment.
CHECKLIST VIOLATION #2: Objects.equals() uses the Objects utility class which is explicitly forbidden. Use direct null-safe comparison instead.
| if (size == elements.length) { | ||
| increaseSize(); | ||
| } | ||
| System.arraycopy(elements, 0, elements, 0, size - index); |
There was a problem hiding this comment.
CRITICAL BUG: This System.arraycopy() call is incorrect and will cause data corruption. It copies the entire array to itself at position 0, overwriting all elements. This line should be removed entirely. The second arraycopy on line 26 handles the shifting correctly.
mateacademy-ai-mentor
left a comment
mateacademy-ai-mentor
left a comment
There was a problem hiding this comment.
Review Summary
Your solution is approved. All functional requirements are met, including proper ArrayList implementation with 1.5x growth factor, correct exception handling, and all required methods working as expected. The critical and medium issues from previous reviews have been successfully addressed. There is one remaining style issue: an empty line between INIT_CAPACITY and elements field declarations at lines 5-7, which is a minor whitespace issue that can be easily cleaned up. This doesn't block progression, but you should remove the blank line between field declarations to fully comply with the checklist requirements. Great work on fixing the previous issues!
✨ Please rate this review in the Platform's notification center1. I will be grateful for your feedback! ✨
Footnotes
2 participants
No description provided.