我正在尝试向我之前创建的对象添加一个元素，但我收到一个错误，即 type {} javascript 上不存在属性

Question

我刚开始学习 javascript，我正在尝试向我之前创建的对象添加一个元素，但我收到一个属性不存在的错误。

我似乎找不到问题，可能是语法错误，但我似乎看不到它，所以如果是这样的话，也许有人可以帮我发现它？

这是对象>

const restaurant = {
  name: 'Classico Italiano',
  location: 'Via Angelo Tavanti 23, Firenze, Italy',
  categories: ['Italian', 'Pizzeria', 'Vegetarian', 'Organic'],
  starterMenu: ['Focaccia', 'Bruschetta', 'Garlic Bread', 'Caprese Salad'],
  mainMenu: ['Pizza', 'Pasta', 'Risotto'],

  openingHours: {
    thu: {
      open: 12,
      close: 22,
    },
    fri: {
      open: 11,
      close: 23,
    },
    sat: {
      open: 0, // Open 24 hours
      close: 24,
    },
  },
  orderD: function ({
    orderName = 'ANON',
    address = 'ANON',
    time = '00:00',
    order = 'ANON',
  }) {
    console.log(`${orderName} has ordered (${order}) to ${address} at ${time}`);
  },
  orderPizza: function (mainIngredient, ...otheringredients) {
    console.log(mainIngredient);
    console.log(otheringredients);
  },
};

然后我在这里尝试添加一个元素。

restaurant.numOfGuests = 0;

但随后它会突出显示元素名称

类型'{ name: string; 上不存在属性'numOfGuests'；位置：字符串；类别：字符串[]；启动菜单：字符串[]；主菜单：字符串[]；开放时间：{周四：{开放：数字；关闭：数字； };星期五：{开放：号码；关闭：数字； };坐：{打开：号码；关闭：数字； }; }; orderD: ({ orderName, address, time, order, }: { ...; }) => void; orderPizza: (mai...'.ts(2339)

我试图忽略它并继续前进，但是当我尝试将新元素记录到控制台时

console.log(numOfGuests);

它给了我这个错误

未捕获的 ReferenceError：未定义 numOfGuests

Answer 1

您似乎没有设置 numOfGuests 属性，如果您的代码是 TypeScript（而不是 JavaScript），这一点很重要。您所要做的就是按照以下代码进行设置。然后，您可以根据需要在任何其他代码中引用它。请参阅Object Types 了解更多信息。

const restaurant = {
  name: 'Classico Italiano',
  location: 'Via Angelo Tavanti 23, Firenze, Italy',
  categories: ['Italian', 'Pizzeria', 'Vegetarian', 'Organic'],
  starterMenu: ['Focaccia', 'Bruschetta', 'Garlic Bread', 'Caprese Salad'],
  mainMenu: ['Pizza', 'Pasta', 'Risotto'],
  numOfGuests: 20,

  openingHours: {
    thu: {
      open: 12,
      close: 22,
    },
    fri: {
      open: 11,
      close: 23,
    },
    sat: {
      open: 0, // Open 24 hours
      close: 24,
    },
  },
  orderD: function({
    orderName = 'ANON',
    address = 'ANON',
    time = '00:00',
    order = 'ANON',
  }) {
    console.log(`${orderName} has ordered (${order}) to ${address} at ${time}`);
  },
  orderPizza: function(mainIngredient, ...otheringredients) {
    console.log(mainIngredient);
    console.log(otheringredients);
  },
};
console.log(restaurant);

如果您使用的是 JavaScript，则不应出现该错误。以如下代码sn-p为例：

const restaurant = {
  name: "Classico Italiano",
  location: "Via Angelo Tavanti 23, Firenze, Italy",
  categories: ["Italian", "Pizzeria", "Vegetarian", "Organic"],
  starterMenu: ["Focaccia", "Bruschetta", "Garlic Bread", "Caprese Salad"],
  mainMenu: ["Pizza", "Pasta", "Risotto"],

  openingHours: {
    thu: {
      open: 12,
      close: 22
    },
    fri: {
      open: 11,
      close: 23
    },
    sat: {
      open: 0, // Open 24 hours
      close: 24
    }
  },
  orderD: function({
    orderName = "ANON",
    address = "ANON",
    time = "00:00",
    order = "ANON"
  }) {
    console.log(`${orderName} has ordered (${order}) to ${address} at ${time}`);
  },
  orderPizza: function(mainIngredient, ...otheringredients) {
    console.log(mainIngredient);
    console.log(otheringredients);
  }
};
restaurant.numOfGuests = 20;
console.log(restaurant);