poll method

E? poll()

Retrieves and removes the head of this queue.

Returns null if this queue is empty.

Example:

final queue = LinkedQueue<String>();
queue.offer('hello');
final polled = queue.poll(); // 'hello'
final empty = queue.poll(); // null

Implementation

E? poll() {
  if (_head == null) {
    return null;
  }

  final data = _head!.data;
  _removeNode(_head!);
  return data;
}