如何根据其中一个值中的数据将对象拆分为多个对象[数组中的唯一值]

Question

我希望根据 StudentID 拆分以下数据。 我知道我必须将 StudentID 中的每个元素与其他每个元素进行比较，如果我们遇到一个新的 studentID，我必须将数据推送到一个新对象中，但我不知道如何实现这一点，因为我是编程新手。

输入数据：

data=[{"StudentID":["1","1","1","1","2","2","2","2","3","3","3","3","4","4","4","4"],
    "ModuleCode:"DES3095-N",
    "WeekNum":["1","2","3","4","1","2","3","4","1","2","3","4","1","2","3","4"],
    "Status":["p","p","pdg","p","abs","cc","p","abs","p","p","abs","p","p","abs","abs","abs"]}]

我试图实现的输出是：

[{"StudentID":1,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","pdg","p"]}
{"StudentID":2,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["abs","cc","p","abs"]}
{"StudentID":3,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","abs","p"]}
{"StudentID":4,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","abs","abs","abs"]}]

我的最终目标是使用 D3.js 绘制给定模块的学生平均出勤率。 PS 原始数据集要大得多。

Answer 1

好的，您拥有的数据结构有点奇怪（数据是数组中的单个对象 - 所以不清楚是否总是如此，或者您是否希望该数组中有多个对象）但让我们看看我们能做什么：

 const data = [ { "StudentID":["1","1","1","1","2","2","2","2","3","3","3","3","4","4","4","4"], "ModuleCode": "DES3095-N", "WeekNum":["1","2","3","4","1","2","3","4","1","2","3","4","1","2","3","4"], "Status":["p","p","pdg","p","abs","cc","p","abs","p","p","abs","p","p","abs","abs","abs"] }/*, { "StudentID":["1","1","1","1","2","2","2","2","3","3","3","3","4","4","4","4"], "ModuleCode": "DES4095-P", "WeekNum":["1","2","3","4","1","2","3","4","1","2","3","4","1","2","3","4"], "Status":["p","p","pdg","p","abs","cc","p","abs","p","p","abs","p","p","abs","abs","abs"] }*/ ]; /* The Goal output is: [{"StudentID":1,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","pdg","p"]}, {"StudentID":2,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["abs","cc","p","abs"]}, {"StudentID":3,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","abs","p"]}, {"StudentID":4,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","abs","abs","abs"]}] */ //The code to achieve that: function aggregateData(data){ const output = []; for (let obj of data){ let temp_arr = []; //incase we have multiple objects in our data array for (let key in obj){ if (Array.isArray(obj[key])){ //console.log('array', obj[key]) if (key == "StudentID"){ let temp_index = 0; for (let item of obj[key]){ if (item != temp_index){ temp_arr.push({"studentID": item}) temp_index = parseInt(item); } } } else{ //not studentID let temp_index = 0; for (let i = 0; i < obj[key].length; i++){ temp_index = parseInt(obj["StudentID"][i]); if (temp_arr[temp_index - 1].hasOwnProperty(key)){ temp_arr[temp_index - 1][key].push(obj[key][i]); } else { temp_arr[temp_index - 1][key] = [obj[key][i]]; } } } } else { //console.log('string', obj[key])+ for (let i = 0; i < temp_arr.length; i++){ if (temp_arr[i].hasOwnProperty(key)){ temp_arr[i][key].push(obj[key]); } else { temp_arr[i][key] = obj[key]; } } } } output.push(temp_arr); } return output; } console.log(aggregateData(data));

输出是：

[
  [
    {"StudentID":1,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","pdg","p"]},
    {"StudentID":2,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["abs","cc","p","abs"]},
    {"StudentID":3,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","abs","p"]},
    {"StudentID":4,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","abs","abs","abs"]}
  ]
]

请注意，它包含在比您在问题中想要的多一个数组中，因为尚不清楚您的数据数组是否包含多个元素（即可能用于另一个模块代码或其他内容），因此我将其设置得尽可能通用.

例如，如果我们将其作为输入：

const data = [
    {
    "StudentID":["1","1","1","1","2","2","2","2","3","3","3","3","4","4","4","4"],
    "ModuleCode": "DES3095-N",
    "WeekNum":["1","2","3","4","1","2","3","4","1","2","3","4","1","2","3","4"],
    "Status":["p","p","pdg","p","abs","cc","p","abs","p","p","abs","p","p","abs","abs","abs"]
    },
    {
    "StudentID":["1","1","1","1","2","2","2","2","3","3","3","3","4","4","4","4"],
    "ModuleCode": "DES4095-P",
    "WeekNum":["1","2","3","4","1","2","3","4","1","2","3","4","1","2","3","4"],
    "Status":["p","p","pdg","p","abs","cc","p","abs","p","p","abs","p","p","abs","abs","abs"]
    }
  ];

然后我们将其作为输出（即每个模块代码的数组）：

[
  [
    {"StudentID":1,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","pdg","p"]},
    {"StudentID":2,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["abs","cc","p","abs"]},
    {"StudentID":3,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","p","abs","p"]},
    {"StudentID":4,"ModuleCode:"DES3095-N","WeekNum":["1","2","3","4"],"Status":["p","abs","abs","abs"]}
  ],
  [
    {"StudentID":1,"ModuleCode:"DES4095-P","WeekNum":["1","2","3","4"],"Status":["p","p","pdg","p"]},
    {"StudentID":2,"ModuleCode:"DES4095-P","WeekNum":["1","2","3","4"],"Status":["abs","cc","p","abs"]},
    {"StudentID":3,"ModuleCode:"DES4095-P","WeekNum":["1","2","3","4"],"Status":["p","p","abs","p"]},
    {"StudentID":4,"ModuleCode:"DES4095-P","WeekNum":["1","2","3","4"],"Status":["p","abs","abs","abs"]}
  ]
]

我们可以通过先转换为 Map 然后使用一些 map filter reduce 函数来做到这一点，但这也可以做到这一点。