javascript - 用位置替换数组中的对象

Question

该函数将一个对象添加到数组中，并使其在列表中排在第二位。但在这种情况下，我紧紧抓住对象，我知道他创建后的编号是多少（5）。如何使它始终被添加到第二个？

const arr = [{
    "name": "BMW",
    "price": "55 000",
    "country": "Germany",
    "certificate": "yes"
  },
  {
    "name": "Mercedes-benz",
    "price": "63 000",
    "country": "Germany",
    "certificate": "yes"
  },
  {
    "name": "Mitsubishi",
    "price": "93 000",
    "constructor": "Bar John",
    "door": "3",
    "country": "Japan",
  },
  {
    "name": "TOYOTA",
    "price": "48 000",
    "max_people": "7",
    "country": "Japan",
    "certificate": "yes"
  },
  {
    "name": "Volkswagen",
    "price": "36 000",
    "constructor": "Pier Sun",
    "country": "Germany",
    "certificate": "no"
  },
];

function pushArr(arr, item) {
  arr.push(item);
  arr[5] = [arr[1], arr[1] = arr[5]][0];
}

let newArr = pushArr(arr, {
  "name": "Audi",
  "price": "89 000",
  "constructor": "Adolf Trump",
  "country": "Germany",
  "certificate": "yes"
});

console.log(arr);

标签： javascriptarraysmethods

Answer 1

const arr = [{
    "name": "BMW",
    "price": "55 000",
    "country": "Germany",
    "certificate": "yes"
  },
  {
    "name": "Mercedes-benz",
    "price": "63 000",
    "country": "Germany",
    "certificate": "yes"
  },
  {
    "name": "Mitsubishi",
    "price": "93 000",
    "constructor": "Bar John",
    "door": "3",
    "country": "Japan",
  },
  {
    "name": "TOYOTA",
    "price": "48 000",
    "max_people": "7",
    "country": "Japan",
    "certificate": "yes"
  },
  {
    "name": "Volkswagen",
    "price": "36 000",
    "constructor": "Pier Sun",
    "country": "Germany",
    "certificate": "no"
  },
];

function pushArr(arr, item) {
  let n = arr.length;
  arr.push(item);
  arr[n] = [arr[1], arr[1] = arr[n]][0];
}

let newArr = pushArr(arr, {
  "name": "Audi",
  "price": "89 000",
  "constructor": "Adolf Trump",
  "country": "Germany",
  "certificate": "yes"
});

let newArr2 = pushArr(arr, {
  "name": "Audi2",
  "price": "100 000",
  "constructor": "Adolf Trump",
  "country": "Germany",
  "certificate": "yes"
});

console.log(arr);