我一直在尝试构建一个选择框，它将通过点击按钮动态添加。我可以添加和删除选择框，但问题是，每当我从数组中删除一个项时，其余元素上的选定选项不会相应更新。如果我从最后一个索引中删除一个元素，它工作得很好，每当项目从开头或中间删除时，问题就会发生。这是我目前所掌握情况

type RailcardsProps = {
  value: string,
  fieldName: string,
  count: string;
}

const railCardsList = [
  {
    text: 'Select Rail card',
    value: ''
  },
  {
    text: 'Child Saver',
    value: 'childSaver'
  },
  {
    text: 'Adult Saver',
    value: 'adultSaver'
  },
  {
    text: 'Senior Railcard',
    value: 'seniorRailcard'
  },
  {
    text: 'Network Railcard',
    value: 'networkRailcard'
  },
]

const PassangerDropdown = () => {
  const [railCards, setRailCards] = useState<RailcardsProps[]>([]);

  const handleRailCardCLick = () => {
    const railCardsArray = railCards;
    const count = railCardCount;
    setRailCards(railCardsArray.concat({
      value: 'Select Rail Card',
      fieldName: `railcard-${railCardCount}`,
      count: '1'
    }));

    setRailCardCount(count + 1);
  }

  useEffect(() => {
    console.log(railCards);
  }, [railCards])

  const handleSelectRailcard = (event: ChangeEvent<HTMLSelectElement>) => {
    const value = (event.target.value);
    const updatedRailCards = railCards;
    const index = event.target.getAttribute('data-index')!;
    updatedRailCards[+index].value = value;
    setRailCards([...updatedRailCards]);
  }

  const handleRailcardCount = (event: ChangeEvent<HTMLSelectElement>) => {
    const count = (event.target.value);
    const updatedRailCards = railCards;
    const index = event.target.getAttribute('data-index')!;
    updatedRailCards[+index].count = count;
    setRailCards([...updatedRailCards]);
  }

  const handleRemoveRailcard = (index: number) => {
    const updatedRailCards = railCards;
    const count = railCardCount;
    updatedRailCards.splice(index, 1);
    setRailCardCount(count - 1);
    console.log(index);
    setRailCards([...updatedRailCards]);
  }

return (
<div className="passanger-dropdown-item--left w-100">
                  <button type="button" className="btn custom-link mb-2" onClick={handleRailCardCLick}>Add Railcards</button>
                  {
                    railCards.map(({ value, fieldName, count }, index) => (
                      <div key={index} className="passanger-dropdown-item--content p-0">
                        <select
                          defaultValue={value}
                          name={fieldName}
                          className="form-control passanger-dropdown-item--select w-70 mr-1"
                          data-index={index}
                          onChange={handleSelectRailcard} >
                          {
                            railCardsList.map(({ value, text }) => (
                              <option key={value} defaultValue={value}>{text}</option>
                            ))
                          }
                        </select>
                        <select
                          defaultValue={count}
                          name={`${fieldName}-count`}
                          className="form-control passanger-dropdown-item--select w-30"
                          data-index={index}
                          disabled={value === 'Select Rail Card'}
                          onChange={handleRailcardCount} >
                          {
                            ['1', '2', '3', '4', '5', '6', '7', '8', '9'].map((item) => (
                              <option key={item} defaultValue={item}>{item}</option>
                            ))
                          }
                        </select>
                        <button
                          type="button"
                          className="btn passanger-dropdown-item--btn"
                          onClick={() => handleRemoveRailcard(index)}>x</button>
                      </div>
                    ))
                  }
                </div>)
}

在this site乘客下拉列表中我试图实现的东西，在乘客下拉列表中我们可以添加或删除rail cards，我如何解决这个问题？