将数组中相同键的值合并到值数组

Question

我的数组如下所示const arr = [      {        "devices": "delete"      },      {        "devices": "update"      },      {        "devices": "read"      },      {        "alerts":"read"      }    ]我必须如下更改格式：const dict =  {"devices": ["update","read"],"alerts": ["read"]}有没有最佳方法来实现这一目标？

Answer 1

你可以减少它！

const arr = [

      {

        "devices": "delete"

      },

      {

        "devices": "update"

      },

      {

        "devices": "read"

      },

      {

        "alerts":"read"

      }

    ]

    

let dict = arr.flatMap(el => Object.entries(el)).reduce((a,[key, value]) => {

   if(key in a) {

      a[key].push(value);

      return a;

   }

   a[key] = [value];

   return a;

},{})

console.log(dict);

Answer 2

是的。您需要创建一个空字典。如果字典中不存在项目或键，则在字典中创建键并分配一个空数组。现在将项目插入其中。

const arr = [{

    "devices": "delete"

  },

  {

    "devices": "update"

  },

  {

    "devices": "read"

  },

  {

    "alerts": "read"

  }

];

const dict = {};

arr.forEach(item => {

  const key = Object.keys(item);

  if (!dict[key]) {

    dict[key] = [];

  }

  dict[key].push(item[key]);

})

console.log(dict);