将对象列表转换为嵌套的对象列表 javascript

Question

我是新手JS。我有一个如下所示的对象列表，

var a = [
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'ram'
  },
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'sam'
  },
  {
    wa_id: 1,
    wa_property_id: 'p2',
    wa_view_name: 'kam'
  },
  {
    wa_id: 2,
    wa_property_id: 'p5',
    wa_view_name: 'pri'
  },
   {
    wa_id: 1,
    wa_property_id: 'p3',
    wa_view_name: 'ste',
  },
]

我想遍历这些对象并创建一个新的单独对象。我想要如下所需的输出

所需输出：

  {
        "1": {
            "p1": ["ram", "sam"],
            "p2": ["kam"],
            "p3": ["ste"]
        },
        "2": {
            "p5": ["pri"]
        }
    }

这是我试过的代码，

var a = [
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'ram'
  },
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'sam'
  },
  {
    wa_id: 1,
    wa_property_id: 'p2',
    wa_view_name: 'kam'
  },
  {
    wa_id: 2,
    wa_property_id: 'p5',
    wa_view_name: 'pri'
  },
   {
    wa_id: 1,
    wa_property_id: 'p3',
    wa_view_name: 'ste',
  },
]

Answer 1

您可以尝试将数组减少为对象

var a = [
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'ram'
  },
  {
    wa_id: 1,
    wa_property_id: 'p1',
    wa_view_name: 'sam'
  },
  {
    wa_id: 1,
    wa_property_id: 'p2',
    wa_view_name: 'kam'
  },
  {
    wa_id: 2,
    wa_property_id: 'p5',
    wa_view_name: 'pri'
  },
   {
    wa_id: 1,
    wa_property_id: 'p3',
    wa_view_name: 'ste',
  },
]

let result = a.reduce((acc,rec) =>{

//if result object doesn't contain key for wa_id - add new id key
if(!(Object.keys(acc).includes(rec.wa_id.toString())))
{
  return {...acc, [rec.wa_id]: {[rec.wa_property_id]:[rec.wa_view_name]}}
}

//if result id object doesn't contain key for property - add new property key
if(!(Object.keys(acc[rec.wa_id]).includes(rec.wa_property_id.toString())))
{
    acc[rec.wa_id] = {...acc[rec.wa_id],[rec.wa_property_id]:[rec.wa_view_name] }
  return acc
}

//otherwise add new value to array of properties
acc[rec.wa_id][rec.wa_property_id] = [...acc[rec.wa_id][rec.wa_property_id], rec.wa_view_name]
return acc
},{})

console.log(result)