在子对象键上对 javascript 对象数组进行排序答案

【问题标题】：Sort javascript array of objects on subobject key在子对象键上对 javascript 对象数组进行排序
【发布时间】：2020-08-22 18:30:04
【问题描述】：

我有一个对象数组，其中包含这样的子对象；

var array=[
  {
    "EmployeeName": "John",
    "Experience": "12",
    "data":{
      "Technology":"SharePoint"
    }
  },
  {
    "EmployeeName": "Charles",
    "Experience": "9",
      "data":{
      "Technology":"ASPNET"
    }
  },
  {
    "EmployeeName": "Jo",
    "Experience": "3",
       "data":{
      "Technology":"PHP"
    }
  },
  {
    "EmployeeName": "Daine",
    "Experience": "7",
      "data":{
      "Technology":"javascript"
    }
  },
  {
    "EmployeeName": "Zain",
    "Experience": "6",
     "data":{
      "Technology":"Unity"
    }
  }
];

现在，我想根据子对象键“技术”对这个数组进行排序。我正在使用这里的示例：https://jsfiddle.net/KSPriyaranjan/4Lzr0qux

当它从基础对象中排序时，它就完成了这项工作，但是我如何让它工作：

function GetSortOrder(prop){
   return function(a,b){
      if( a[prop] > b[prop]){
          return 1;
      }else if( a[prop] < b[prop] ){
          return -1;
      }
      return 0;
   }
}

array.sort( GetSortOrder("data.Technology") );

document.write("<br><br> Sorted Technology Names : <br>");

for (var item in array) {
 document.write("<br>"+array[item].Technology);
}

这会产生这个：

Sorted Technology Names :

undefined
undefined
undefined
undefined

希望有人可以在这件事上提供帮助，并在此先感谢 :-) 未定义

【问题讨论】：

a["data.Technology"] 与a["data"]["Technology"] 不同。

标签： javascript arrays sorting

【解决方案1】：

如果传递的属性包含任何.s，请使用reduce 导航到比较之前的最后一个嵌套值：

const GetSortOrder = (accessor) => {
  const getVal = accessor.includes('.')
    ? outer => accessor.split('.').reduce((a, prop) => a[prop], outer)
    : outer => outer;
  return (a, b) => getVal(a).localeCompare(getVal(b));
};

var array=[
  {
    "EmployeeName": "John",
    "Experience": "12",
    "data":{
      "Technology":"SharePoint"
    }
  },
  {
    "EmployeeName": "Charles",
    "Experience": "9",
      "data":{
      "Technology":"ASPNET"
    }
  },
  {
    "EmployeeName": "Jo",
    "Experience": "3",
       "data":{
      "Technology":"PHP"
    }
  },
  {
    "EmployeeName": "Daine",
    "Experience": "7",
      "data":{
      "Technology":"javascript"
    }
  },
  {
    "EmployeeName": "Zain",
    "Experience": "6",
     "data":{
      "Technology":"Unity"
    }
  }
];
const GetSortOrder = (accessor) => {
  const getVal = accessor.includes('.')
    ? outer => accessor.split('.').reduce((a, prop) => a[prop], outer)
    : outer => outer;
  return (a, b) => getVal(a).localeCompare(getVal(b));
};
array.sort( GetSortOrder("data.Technology") );
console.log(array);

条件不是绝对必要的（尽管您可能认为它可以使意图更清晰），您也可以这样做

const getVal = outer => accessor.split('.').reduce((a, prop) => a[prop], outer)

【讨论】：

【解决方案2】：

技术不是您的对象的属性。它是您的 object.data 的一个属性。

尝试改变 javascript array[item].Technology 到 array[item].data.Technology

【讨论】：

【解决方案3】：

您可以通过保持比较方法添加一个函数来获取值。

function GetSortOrder(prop) {
    const
        keys = prop.split('.'),
        getValue = object => keys.reduce((o, k) => o[k], object);
    
    return function(a, b) {
        const
            left = getValue(a),
            right = getValue(b);
        if (left > right) return 1;
        else if (left < right) return -1;
        return 0;
    }
}

var array = [{ EmployeeName: "John", Experience: "12", data: { Technology: "SharePoint" } }, { EmployeeName: "Charles", Experience: "9", data: { Technology: "ASPNET" } }, { EmployeeName: "Jo", Experience: "3", data: { Technology: "PHP" } }, { EmployeeName: "Daine", Experience: "7", data: { Technology: "javascript" } }, { EmployeeName: "Zain", Experience: "6", data: { Technology: "Unity" } }];

array.sort(GetSortOrder("data.Technology"));
console.log(array);

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【讨论】：