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javascript - 如何使用 lodash 对多个进行分组

问题描述

我有以下数组

const array = [
  {
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'NY', country: 'USA' },
    className: 'FourthActivity',
    deviceId: '1111111111111111'
  },
  { 
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'NY', country: 'USA' },
    className: 'FourthActivity',
    deviceId: '222222222222222'
  },
  {
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'Landon', country: 'UK' },
    className: 'FourthActivity',
    deviceId: '33333333333'
 }
]

我必须通过使用对象内部的两个属性（即address和className. 我如何使用 loadash 或 javascript 来做到这一点？

预期产出

[{
  address: { city: 'NY', country: 'USA' }, className: 'FourthActivity',
  count: 2,
  data: [{
    deviceId: 222222222222222,
  }, {
    deviceId: 1111111111111111,
  }]
}, {
  address: { city: 'Landon', country: 'UK' }, className: 'FourthActivity',
  count: 1,
  data: [{
    deviceId: 33333333333,
  }]
}]

我试过这个但不起作用

var selectedVehicle = _.filter(array, 'address')

  const selectedVehicles = _.groupBy(selectedVehicle, function(item) {
  return item.makeCode;
})

console.log(selectedVehicles)

标签： javascriptarrayslodash

解决方案

您可以reduce进入一个对象，{ address, className, count: 0, data: [] }如果给定的地址/类名对尚不存在，则创建该对象，然后获取该对象的值：

const array = [
  {
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'NY', country: 'USA' },
    className: 'FourthActivity',
    deviceId: '1111111111111111'
  },
  { 
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'NY', country: 'USA' },
    className: 'FourthActivity',
    deviceId: '222222222222222'
  },
  {
    key: 'TSJUcgLGig2UOdjAzlqq4KW5GK6PKXHC2ndw40HYIss7EKsV6nJ',
    location: { lat: '22.7196', lng: '75.8577' },
    address: { city: 'Landon', country: 'UK' },
    className: 'FourthActivity',
    deviceId: '33333333333'
 }
]
const output = Object.values(array.reduce((a, { address, className, deviceId }) => {
  const addressClassNameStr = JSON.stringify({ address, className });
  if (!a[addressClassNameStr]) {
    a[addressClassNameStr] = { address, className, count: 0, data: [] };
  }
  a[addressClassNameStr].count++;
  a[addressClassNameStr].data.push({ deviceId });
  return a;
}, {}));
console.log(output);

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