C# | List.TrimExcess Method
List<T>.TrimExcess Method is used to set the capacity to the actual number of elements in the List<T>, if that number is less than a threshold value.
public void TrimExcess ();
- This method can be used to minimize a collection’s memory overhead if no new elements will be added to the collection.
- To reset a List<T> to its initial state, call the Clear method before calling TrimExcess method.
- Trimming an empty List<T> sets the capacity of the List<T> to the default capacity.
- The cost of reallocating and copying a large List<T> can be considerable, however, so the TrimExcess method does nothing if the list is at more than 90 percent of capacity. This avoids incurring a large reallocation cost for a relatively small gain.
- This method is an O(n) operation, where n is Count.
Below programs illustrate the use of List<T>.TrimExcess Method:
8 5 5 5
16 9 9 9 9 0