javascript - 使用 Lodash 合并共享键值对上的对象

Question

我有两个对象数组 weather 和 power，我想将它们合并到共享属性 date 上。有没有办法用 lodash 做到这一点？

 const weather = [
  {
    date: 2,
    weather: 2
  },
  {
    date: 1,
    weather: 1
  },
  {
    date: 3,
    weather: 3
  }
  ];

  const power = [
  {
    date: 1,
    power: 10
  },
  {
    date: 2,
    power: 20
  }];

  const merged = _.merge(weather, power); // <- This does not work as hoped for

预期输出仅包含具有匹配 date 字段的对象(因此 weather 数组中的 date: 3 对象被丢弃).

  const expected = [{
    date: 1,
    weather: 1,
    power: 10
  },
  {
    date: 2,
    weather: 2,
    power: 20
  }];

我觉得这应该可以通过 union、unionBy、merge 或类似的方式实现，但我在文档中找不到匹配的示例.

Answer 1

通过使用 _.keyBy('date') 索引数组来创建索引对象，合并索引，并使用 _.values() 提取值:

const weather = [{"date":2,"weather":2},{"date":1,"weather":1},{"date":3,"weather":3}];

const power = [{"date":1,"power":10},{"date":2,"power":20}];

const weatherIndex = _.keyBy(weather, 'date');
const powerIndex = _.keyBy(power, 'date');

const result = _(powerIndex)
  .pick(_.keys(weatherIndex))
  .merge(_.pick(weatherIndex, _.keys(powerIndex)))
  .values()
  .value();

console.log(result);

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