# add method

1. @override

void add(

1. E element

)
override

Adds `value` to the end of this list, extending the length by one.

The list must be growable.

    final numbers = <int>[1, 2, 3];
    numbers.add(4);
    print(numbers); // [1, 2, 3, 4]

## Implementation

    @override
    void add(E element) {
      final newNode = _Node(element);
      if (_head == null) {
        _head = newNode;
        _tail = newNode;
      } else {
        _tail!.next = newNode;
        newNode.prev = _tail;
        _tail = newNode;
      }
      _length++;
    }