StateMachineStudy/StateMachine/CarStateMachine/Model/Car.cs

namespace CarStateMachine.Model
{
    public class Car
    {
        public enum State
        {
            Stopped,
            Started,
            Running,
        }

        public enum Action
        {
            Stop,
            Start,
            Accelerate,
        }

        private State _state = State.Stopped;
        public State CurrentState { get { return _state; } }

        public void TakeAction(Action action)
        {
            State state = _state;
            switch (_state, action)
            {
                case (State.Stopped, Action.Start):
                    state = State.Started;
                    break;
                case (State.Started, Action.Accelerate):
                    state = State.Running;
                    break;
                case (State.Started, Action.Stop):
                    state = State.Stopped;
                    break;
                case (State.Running, Action.Stop):
                    state = State.Stopped;
                    break;
            }

            _state = state;

            // _state = (_state, action) switch
            // {
            //     (State.Stopped, Action.Start) => State.Started,
            //     (State.Started, Action.Accelerate) => State.Running,
            //     (State.Started, Action.Stop) => State.Stopped,
            //     (State.Running, Action.Stop) => State.Stopped,
            //     _ => _state
            // };
        }
    }
}