如何从 javascript 中具有相同键的对象创建对象数组，对象中包含数组

Question

我有一个看起来像这样的对象数组

[{
        "name": "Agile Process",
        "id": 27,
        "score": 3,
        "source": "Self"
    },{
        "name": "Agile Process",
        "id": 27,
        "score": 4,
        "source": "Trainer"
    },{
        "name": "2 & 3 Tier Architecture",
        "id": 37,
        "score": 4,
        "source": "Self"
    },{
        "name": "2 & 3 Tier Architecture",
        "id": 37,
        "score": 5,
        "source": "Trainer"
 }]

我也想做这样的东西，一直在努力，但似乎没有掌握。

[
    {
        "name": "Agile Process",
        "id": 7,
        "data": [
            {
                "score": 3,
                "source": "Self"
            },{
                "score": 4,
                "source": "Trainer"
            }
        ]
    },
    {
        "name": "2 & 3 Tier Architecture",
         "id": 37,
         "data": [
            {
                "score": 4,
                "source": "Self"
            },{
                "score": 5,
                "source": "Trainer"
            }]
        }
  ];

我该如何解决这个问题？

Answer 1

这是一个纯粹的 javascript 解决方案：在初始数组上使用 reduce 方法，使用结果数组（最初为空）作为累加器，它将存储转换后的数据。当 reduce 方法循环遍历初始数组的项目时，检查结果数组是否包含具有当前项目 id 的元素。如果是这样，则只需向其中添加新数据，否则在结果数组中创建一个新项。

var data = [{
        "name": "Agile Process",
        "id": 27,
        "score": 3,
        "source": "Self"
    },{
        "name": "Agile Process",
        "id": 27,
        "score": 4,
        "source": "Trainer"
    },{
        "name": "2 & 3 Tier Architecture",
        "id": 37,
        "score": 4,
        "source": "Self"
    },{
        "name": "2 & 3 Tier Architecture",
        "id": 37,
        "score": 5,
        "source": "Trainer"
 }];



var newData = [];

newData = data.reduce(function(acc, current) {
  var existingArr = acc.filter(function(x) { return x.id === current.id });
  if(existingArr.length === 0) {
    acc.push({ name: current.name, id: current.id, data: [{ score: current.score, source: current.source }] });
  }
  else {
    existingArr[0].data.push({ score: current.score, source: current.source });
  }
  return acc;
}, newData);

Answer 2

一种可能的方法：

_.values(_.reduce(arr, function(acc, el) {
  var id = el.id;
  if (!acc.hasOwnProperty(id)) {
    acc[id] = _.pick(el, 'id', 'name');
    acc[id].data = [];
  }
  acc[id].data.push(_.pick(el, 'score', 'source'));
  return acc;
}, {}));

Demo。当您需要将事物分组时，这是一种常用方法。

Answer 3

此版本使用 groupBy 按 id 对项目进行分组，然后映射到每个分组以创建所需的对象：

var groupToItem = function(items){
    return {
        id: items[0].id,
        name: items[0].name,
        data: _.map(items, function(item){
            return _.pick(item, 'score', 'source');
        })
    }
 }

 var result = _.chain(data)
    .groupBy('id')
    .map(groupToItem)
    .value();

Answer 4

普通 Javascript 解决方案，但仅适用于您的特定数据结构：

function groupObjectsById(array){
    var output = [];
    var ids = [];
    for(var i = 0; i < array.length; i++){
        var current = array[i];
        if(ids.indexOf(current.id) > -1){
            var objInOutput = output.filter(function(obj){
                if(obj.id === current.id){
                    return obj;
                }
            })[0];
            var dataObj = { score: current.score, source: current.source};
            objInOutput.data.push(dataObj);
        }else{
            var outputObject = {name: current.name, id: current.id};
            outputObject.data = [{ score: current.score, source: current.source}];          
            output.push(outputObject);
            ids.push(current.id);
        }
    }
    return output;
}

如何从 javascript 中具有相同键的对象创建对象数组，对象中包含数组

how do I create an array of objects with array in the object from an object with the same key in javascript

javascript

arrays

node.js

underscore.js

lodash