DSA in DartMedium30 XP4 min read
How do you implement a linked list in Dart?
TL;DR: Build a Node<T> class with value and next pointer. A LinkedList<T> holds a head reference. O(1) prepend/insert at head, O(n) access by index. Dart's built-in LinkedList<LinkedListEntry> also provides a doubly-linked list.
Full Answer
Linked lists are rarely needed in Flutter (List covers most cases), but they appear in DSA interviews and are useful for understanding pointer-based structures.
When to use over List
- ▸Frequent insert/delete at front: O(1) for linked list vs O(n) for array List
- ▸Unknown size: no array resizing overhead
- ▸Memory: each node allocates separately — no large contiguous block needed
🎯
Dart's dart:collection LinkedList<E extends LinkedListEntry<E>> provides a doubly-linked list with O(1) insertion and removal given a node reference.
Code Examples
dartSingly linked list in Dart
Output
2
Common Mistakes
- ✗Using Node?.next without null checks — Dart's null safety requires explicit null handling
- ✗Using linked list for random access — O(n) per access; use List for that
Interview Tip
💡
Be ready to reverse a linked list in O(n) — classic interview question. Show the three-pointer technique: prev, curr, next.
#linked-list#node#pointer#data-structure