合并2个对象数组以创建对象映射

Question

I'm receiving the following data in my JS from a WebService :

{
  "fire": {
    "totalOccurence": 2,
    "statsByCustomer": [
      {
        "idCustomer": 1,
        "occurence": 1
      },
      {
        "idCustomer": 2,
        "occurence": 1
      }
    ]
  },
  "flood": {
    "totalOccurence": 1,
    "statsByCustomer": [
      {
        "idCustomer": 1,
        "occurence": 1
      }
    ]
  }
}

What's the fastest way to create the following object as a result :

{
  "1": {
    "fire": 1,
    "flood": 1
  },
  "2": {
    "fire": 1,
    "flood": 0
  }
}

I'm actually doing multiple forEach to format the data myself, but i think it's pretty ugly and not efficient.. PS : the key for the result map is the customer Id

Any idea on how to do this the right way?

Thanks for your help !

Answer 1

You could iterate the outer object's keys and then the inner arrays. If an result object does not exist, create one with the wanted keys and zero values.

 var data = { fire: { totalOccurence: 2, statsByCustomer: [{ idCustomer: 1, occurence: 1 }, { idCustomer: 2, occurence: 1 }] }, flood: { totalOccurence: 1, statsByCustomer: [{ idCustomer: 1, occurence: 1 }] } }, result = {}, keys = Object.keys(data); keys.forEach(function (k) { data[k].statsByCustomer.forEach(function (a) { if (!result[a.idCustomer]) { result[a.idCustomer] = {}; keys.forEach(function (kk) { result[a.idCustomer][kk] = 0; }); } result[a.idCustomer][k] += a.occurence; }); }); console.log(result); 

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