Stack example

main.dart

void main() {
  final stack = Stack<int>.of([42, 12, 1000]);
  
  // final stack = Stack<int>();
  // stack.push(42);
  // stack.push(12);
  // stack.push(1000);
  
  final lastValue = stack.pop();
  final letsPeek = stack.peek();
  print(stack);
  print(stack.peek());
}

class Stack<E> {
  // constructor
  Stack() : _list = [];

  // named constructor
  Stack.of(this._list);

  final List<E> _list;

  void push(E item) => _list.add(item);

  E pop() => _list.removeLast();

  E peek() => _list.last;

  bool get isEmpty => _list.isEmpty;

  @override
  String toString() {
    const top = '---Top---\n';
    final middle = _list.reversed.join('\n');
    const bottom = '\n---------';
    return '$top$middle$bottom';
  }
}

If your function only has one line you can use => instead of return.