Javascript通过互值减少对象数组答案

【问题标题】：Javascript reduce array of objects by mutual valueJavascript通过互值减少对象数组
【发布时间】：2021-09-27 05:55:12
【问题描述】：

如何将对象数组减少为新的合并对象数组？我将以下数组与地点及其子区域混合在一起。我想将 sub_main_places 添加到 main_places，如下所示：

 "unformatted places": [
    {
      "name": "main_place1",
      "address": "place_address1"
    },
    {
      "name": "main_place2",
      "address": "place_address2"
    },
    {
      "name":"sub_main_place1",
      "address":"sub_main_place_address1"
    },
    {
      "name":"sub_main_place2",
      "address":"sub_main_place_address2"
    }
  ]

我试图达到的结果是：

  "formatted places": [
    {
      "name": "main_place1",
      "address": "place_address1",
      "sub_area": "sub_main_place1"
    },
    {
      "name": "main_place2",
      "address": "place_address2",
      "sub_area": "sub__main_place2"
    }
  ],

【问题讨论】：

您认为如何实现这一目标？你尝试了什么
真正的值是否真的以数字1、2 等结尾？如果不是，您将如何判断这些值应该如何分组？
是的，末尾有数字，但是有错字，应该在数字前加下划线...想法是 split('_').pop() 并比较数字，因为数字始终是一个共同因素，那么如果数字匹配格式新对象。但从那里我不知道。

标签： javascript reduce

【解决方案1】：

使用reduce，您可以使用与主地址对应的键组装对象，然后在遇到子地址时引用这些键。最后，您可以使用 Object.values 将结果转换回数组

let unformatted_places = [{
    "name": "main_place1",
    "address": "place_address1"
  },
  {
    "name": "main_place2",
    "address": "place_address2"
  },
  {
    "name": "sub_main_place1",
    "address": "sub_main_place_address1"
  },
  {
    "name": "sub_main_place2",
    "address": "sub_main_place_address2"
  }
]

let formatted_places = Object.values(unformatted_places
  .sort((a, b) => a.name.localeCompare(b.name))
  .reduce((b, a) => {
    let f = a.name.split('sub_')[1]
    if (a.name.indexOf('sub_') === 0 && b[f]) {
      b[f].sub_area = a.name;
    } else {
      b[a.name] = a;
    }
    return b;
  }, {}))

console.log(formatted_places);

【讨论】：

【解决方案2】：

尝试了另一种方法：

let data_1 = {
  "unformatted places": [{
      "name": "main_place1",
      "address": "place_address1"
    },
    {
      "name": "main_place2",
      "address": "place_address2"
    },
    {
      "name": "sub_main_place1",
      "address": "sub_main_place_address1"
    },
    {
      "name": "sub_main_place2",
      "address": "sub_main_place_address2"
    }
  ]
};

let data_2 = {}

data_1["unformatted places"].forEach(function(dict) {
  var name = dict.name;
  if (name.startsWith("main")) {
    data_2[name] = dict;
  } else if (name.startsWith("sub_")) {
    let key = name.substring(4, name.length);

    if (key in data_2) {
      data_2[key]["sub_area"] = name;
    } else {
      data_2[key] = {
        "sub_area": name
      };
    }

  }
});
data_2 = {
  "formatted places": Object.values(data_2)
}
console.log(data_2);

【讨论】：