javascript - 我想改变我的 json 结构，我该怎么做？

Question

我想改变我的 json 结构，我该怎么做？

我得到一个看起来像这样的json：

data = [
   {
     "fyyear": "2019-2020",
     "kraid": 5,
     "kraname": "CSAT",
     "kracriteria": 18,
     "lowerlimit": 2,
     "upperlimit": 3.99,
     "startrange": 50,
     "endrange": 60
   },
   {
     "fyyear": "2019-2020",
     "kraid": 5,
     "kraname": "CSAT",
     "kracriteria": 18,
     "lowerlimit": 2,
     "upperlimit": 3.99,
     "startrange": 50,
     "endrange": 60
   }
 ]

但我需要它在这个结构中：

data = [{
      "fyyear": "2020-2021",
      "kraid": null,
      "kraname": "",
      "kracriteria": [
         {
           "lowerlimit": "QWER",
           "upperlimit": "QWER",
           "startrange": "QWERT",
           "endrange": "QWERT"
         },
         {
           "lowerlimit": "QWER",
           "upperlimit": "QWERT",
           "startrange": "QWER",
           "endrange": "QWERT"
    },
         {
           "lowerlimit": "QWERT",
           "upperlimit": "QWERT",
          "startrange": "QWERT",
         "endrange": "QWERT"
        }
      ]

标签： javascript

Answer 1

这是一个有意冗长的解决方案，可能会有所帮助，因为您似乎正在学习一些关于 JavaScript 对象和数组的基础知识。

（这可以更简洁地完成Array.prototype.map）

const
  data = getOriginalData(),
  firstItem = data[0],

  // Creates a resultArray containing a single (currently empty) resultObject
  resultObject = {},
  resultArray = [resultObject],

  // Specifies the three kinds of properties for the result object
  propsToCopyFromFirstItem = ["fyyear", "kraid", "kraname"],
  arrayProp = "kracriteria",
  childProps = ["lowerlimit", "upperlimit", "startrange", "endrange"];

// Loops through propsToCopyFromFirstItem:
//   Looks in the first item of `data` for the value to use and
//   creates a property with that name and value in the result object
for (let propName of propsToCopyFromFirstItem){
  let valueForProp = firstItem[propName];
  resultObject[propName] = valueForProp;
}

// Creates a property whose value is an empty array to add items to
// Loops through `data`:
//   Makes an empty `nextItem` obj (to add to the arrayProp in resultObject)
//   Loops through `childProps`:
//     Looks in the currentProperty in the currentObject of `data` for the value 
//     Makes a new prop in nextItem with that name and value
resultObject[arrayProp] = [];
for (let currentObject of data){
  const nextItem = {};
  for (let currentPropName of childProps){
    let valueForProp = currentObject[currentPropName];
    nextItem[currentPropName] = valueForProp;
  }
  // Adds `nextItem` to the array property in resultObject
  resultObject[arrayProp].push(nextItem);
}

// Logs the result (`resultObject` was added to `resultArray` before)
console.log(resultArray);


// Provides the original `data` array
function getOriginalData(){ 
  return [
    {
      "fyyear": "2019-2020",
      "kraid": 5,
      "kraname": "CSAT",
      "kracriteria": 18,
      "lowerlimit": 2,
      "upperlimit": 3.99,
      "startrange": 50,
      "endrange": 60
    },
    {
      "fyyear": "2019-2020",
      "kraid": 5,
      "kraname": "CSAT",
      "kracriteria": 18,
      "lowerlimit": 3,
      "upperlimit": 5.99,
      "startrange": 70,
      "endrange": 80
    }
  ];
}