`ArrayList vs. LinkedList in Java`

LinkedList vs. ArrayList in Java: When to Choose Which?

For Java/Spring Boot developers, the choice between LinkedList and ArrayList hinges on performance needs. ArrayList uses a dynamic array, offering O(1) access time but O(n) insertion/deletion in the middle. LinkedList uses a doubly-linked list, providing O(n) access but O(1) insertion/deletion anywhere.

Use ArrayList when:

• Frequent random access: Need to quickly access elements by index.
• Mostly read operations: Insertions and deletions are infrequent.

ArrayList<Integer> arrayList = new ArrayList<>();
arrayList.add(1);
arrayList.add(2);
int element = arrayList.get(0); // O(1) access

Use LinkedList when:

• Frequent insertions/deletions in the middle: Need efficient mid-list modifications.
• Ordered sequence manipulation: Frequent additions/removals from beginning/end.

LinkedList<Integer> linkedList = new LinkedList<>();
linkedList.add(1);
linkedList.add(2);
linkedList.add(1, 3); // O(1) insertion in the middle
linkedList.remove(0); //O(1) removal from beginning

In short: Prioritize ArrayList for speed of access; LinkedList for speed of modification in the middle. Consider memory usage as LinkedList has higher overhead per element. For Spring Boot, this choice depends on the data structure's role within your application (e.g., a cache might favor ArrayList for rapid lookups).