展平嵌套的 JSON 对象

Question

我有一个这样的 json 对象：

const people = {
name: 'My Name',
cities: [{city: 'London', country: 'UK'},{city: 'Mumbai', country: 'IN'},{city: 'New York', country: 'US'}],
}

我想要这样的输出：即对于每个城市，我想要展平数组。

[
  ['My Name', 'London', 'UK'], 
  ['My Name','Mumbai', 'IN'],
  ['My Name','New York', 'US']
]

我尝试过 flatten 等，但不知道如何实现这一点。 有人可以帮我吗？ 谢谢， 萨西

Answer 1

如果你想要 JSON 输出：

const people = {
  name: 'My Name',
  cities: [{city: 'London', country: 'UK'},{city: 'Mumbai', country: 'IN'},{city: 'New York', country: 'US'}],
}

let result = people.cities.map(data => {
  return {
    name: people.name,
    city: data.city,
    country: data.country
  }
})

console.log(result)

为多人扩展：

const peopleExtended = [{
  name: 'My Name',
  cities: [{
    city: 'London',
    country: 'UK'
  }, {
    city: 'Mumbai',
    country: 'IN'
  }, {
    city: 'New York',
    country: 'US'
  }],
}, {
  name: 'Person 2',
  cities: [{
    city: 'Birmingham',
    country: 'UK'
  }, {
    city: 'Delhi',
    country: 'IN'
  }, {
    city: 'New York',
    country: 'US'
  }],
}]

function flattenCities(person) {
  return person.cities.map(data => {
    return {
      name: person.name,
      city: data.city,
      country: data.country
    }
  })
}

peopleExtended.forEach(person => {
    let flatArray = flattenCities(person);
  console.log(person.name, flatArray)
})

Answer 2

这应该可以解决问题！

const people = {
  name: 'My Name',
  cities: [{city: 'London', country: 'UK'},{city: 'Mumbai', country: 'IN'},{city: 'New York', country: 'US'}],
}

function flattenIt(obj) {
  const name = obj.name;
  const cityData = obj.cities;
  return cityData.map(({city, country}) => [name, city, country])
}

console.log(flattenIt(people));