Published May 13, 2024
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In Dart, the .addAll() method adds all collection elements to the end of a queue. This method is part of the Queue class in the dart:collection library. It is useful for merging two collections where the order of the elements is preserved and duplicates are not removed.


  • queue: The instance of a Queue where elements will be added.
  • collection: The collection of elements to add to the queue. This can be of any class implementing the Iterable interface.

Note: The .addAll() method does not return a value.


In the following example, the .addAll() method takes all elements from the moreNumbers list and adds them to the end of the numbers queue:

import 'dart:collection';
void main() {
Queue<int> numbers = Queue.from([1, 2, 3]);
List<int> moreNumbers = [4, 3, 5, 6];

The output for the above code is:

{1, 2, 3}
{1, 2, 3, 4, 3, 5, 6}

Note: Since the Queue class is part of the dart:collection library, the library must be imported into the code to make Queue work as intended.

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