Both are useful if you need to iterate over elements in sorted order. As a rule of thumb if you creating it once and not modifying it than a SortedList has a faster construction time and uses less memory than a SortedDictionary.
| Operation | SortedList | SortedDictionary |
|---|---|---|
| retrieval by key | O(log(n)) | O(log(n)) |
| insert and remove elements | O(n) | O(log(n)) |
| contains key | O(log(n)) | O(log(n)) |
Sorted Dictionary
- Implemented as binary search tree for fast lookups while keeping elements in sorted order.
Sorted List
- Implemented as two arrays (keys, values) kept in sorted order.
- Faster construction time when being populated in one go.