JavaScript JSON数组排序

Question

我正在尝试为减肥挑战应用程序构建自定义排序功能，当用户尝试单击第1周以对以下JSON格式数据进行排序时，结果似乎不正确。不胜感激，如果您可以指导我在这里所缺少的内容。如果功能正常，我将把第1周更改为另一周。

var array=[
  {
    "user": "Noah",
    "weeklyPercentageChange":["10.37","-3.75","-2.21","-1.85","-1.68","-1.21","-1.41","-1.17","-0.47","-1.64","-23.36"  ]
  },
  {
    "user": "Liam",
    "weeklyPercentageChange":["-4.49","-2.61","-1.19","-0.36","-1.39","-1.29","-0.44","-0.22","-0.67","-0.33","-12.53"  ]
  },
  {
    "user": "Mason",
    "weeklyPercentageChange":["3.22","-2.40","0.35","-1.80","-0.25","-0.66","-2.42","0.00","1.71","-0.52","-9.00"  ]
  },
  {
    "user": "Ethan",
    "weeklyPercentageChange":["-1.31","0.00","-1.75","-0.78","0.61","-1.79","0.80","0.00","0.00","0.38","-3.75"]
  },
  {
    "user": "Alexander",
    "weeklyPercentageChange":["-1.26","0.00","-1.48","-1.50","-0.07","-1.66","-0.53","-0.20","0.00","-0.86","-7.42"]
  },
  {
    "user": "Maria",
    "weeklyPercentageChange":["-1.10","-1.90","-0.11","-0.63","2.52","-1.01","0.06","-0.06","-0.06","1.38","-0.94"  ]
  },
  {
    "user": "Paul",
    "weeklyPercentageChange":["1.08","-2.33","-0.10","-1.17","1.83","-1.70","-1.13","-0.19","0.00","0.00","-5.84"]
  },
  {
    "user": "Steven",
    "weeklyPercentageChange":["-0.77","-2.93","0.19","-1.22","-0.48","-1.39","-1.27","0.00","-0.23","-0.91","-8.84"  ]
  },
  {
    "user": "Edward",
    "weeklyPercentageChange":["-0.71","-1.73","1.46","-0.17","0.42","-1.23","-1.26","1.47","0.59","-2.81","-3.98"]
  },
  {
    "user": "Benjamin",
    "weeklyPercentageChange":["0.56","-0.28","0.80","-0.94","0.00","0.90","-0.05","1.17","-1.87","0.98","0.14"]
  },
  {
    "user": "Zachary",
    "weeklyPercentageChange":["-0.47","-1.29","0.48","-1.59","1.37","-2.65","-0.24","0.66","0.05","0.24","-3.41"]
  },
  {
    "user": "Austin",
    "weeklyPercentageChange":["-0.33","0.00","-3.05","-2.02","0.80","-1.48","1.58","-0.43","0.87","-1.90","-5.87"]
  },
  {
    "user": "Jordan",
    "weeklyPercentageChange":["0.06","-2.18","2.17","-0.56","0.84","-0.67","0.45","0.39","0.28","0.06","0.67"]
  },
  {
    "user": "Gabriel",
    "weeklyPercentageChange":["0.00","0.00","-0.12","-0.81","0.25","0.00","0.00","0.00","0.00","0.00","-0.68"]
  },
  {
    "user": "Wayne",
    "weeklyPercentageChange":["0.20","-3.45","0.35","0.49","0.56","0.00","-0.61","0.54","0.54","-0.41","-1.83"]
  },
  {
    "user": "Willie",
    "weeklyPercentageChange":["-0.83","-3.21","0.71","0.00","-1.05","0.35","0.07","0.14","-0.07","-1.45","-3.72"]
  },
  {
    "user": "Frank",
    "weeklyPercentageChange":["0.00","0.00","-3.04","0.88","1.37","-0.41","-1.21","2.10","0.00","-0.58","-0.94"]
  }
];

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

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

array.sort( GetSortOrder("weeklyPercentageChange[0]") );

document.write("<br><br> Sorted Weekly Percentage Change : <br>");

for (var item in array) {
 document.write("<br>"+array[item].weeklyPercentageChange[0]);
}

Answer 1

[GetSortOrder("weeklyPercentageChange[0]")将导致查找文字属性名称"weeklyPercentageChange[0]"-也就是说，如果对象定义如下

{
  user: 'name',
  'weeklyPercentageChange[0]': 55
}

这不是您所拥有的，这就是为什么事情无法按预期进行的原因。

对于导航嵌套对象或数组以查找要排序的值的一般解决方案，请考虑传递一个回调，该回调导航到要与之比较的嵌套值； obj => obj.weeklyPercentageChange[0]。

您还可以通过简单地返回值之间的差来使代码更加简洁：

var array=[{user:"Noah",weeklyPercentageChange:["10.37","-3.75","-2.21","-1.85","-1.68","-1.21","-1.41","-1.17","-0.47","-1.64","-23.36"]},{user:"Liam",weeklyPercentageChange:["-4.49","-2.61","-1.19","-0.36","-1.39","-1.29","-0.44","-0.22","-0.67","-0.33","-12.53"]},{user:"Mason",weeklyPercentageChange:["3.22","-2.40","0.35","-1.80","-0.25","-0.66","-2.42","0.00","1.71","-0.52","-9.00"]},{user:"Ethan",weeklyPercentageChange:["-1.31","0.00","-1.75","-0.78","0.61","-1.79","0.80","0.00","0.00","0.38","-3.75"]},{user:"Alexander",weeklyPercentageChange:["-1.26","0.00","-1.48","-1.50","-0.07","-1.66","-0.53","-0.20","0.00","-0.86","-7.42"]},{user:"Maria",weeklyPercentageChange:["-1.10","-1.90","-0.11","-0.63","2.52","-1.01","0.06","-0.06","-0.06","1.38","-0.94"]},{user:"Paul",weeklyPercentageChange:["1.08","-2.33","-0.10","-1.17","1.83","-1.70","-1.13","-0.19","0.00","0.00","-5.84"]},{user:"Steven",weeklyPercentageChange:["-0.77","-2.93","0.19","-1.22","-0.48","-1.39","-1.27","0.00","-0.23","-0.91","-8.84"]},{user:"Edward",weeklyPercentageChange:["-0.71","-1.73","1.46","-0.17","0.42","-1.23","-1.26","1.47","0.59","-2.81","-3.98"]},{user:"Benjamin",weeklyPercentageChange:["0.56","-0.28","0.80","-0.94","0.00","0.90","-0.05","1.17","-1.87","0.98","0.14"]},{user:"Zachary",weeklyPercentageChange:["-0.47","-1.29","0.48","-1.59","1.37","-2.65","-0.24","0.66","0.05","0.24","-3.41"]},{user:"Austin",weeklyPercentageChange:["-0.33","0.00","-3.05","-2.02","0.80","-1.48","1.58","-0.43","0.87","-1.90","-5.87"]},{user:"Jordan",weeklyPercentageChange:["0.06","-2.18","2.17","-0.56","0.84","-0.67","0.45","0.39","0.28","0.06","0.67"]},{user:"Gabriel",weeklyPercentageChange:["0.00","0.00","-0.12","-0.81","0.25","0.00","0.00","0.00","0.00","0.00","-0.68"]},{user:"Wayne",weeklyPercentageChange:["0.20","-3.45","0.35","0.49","0.56","0.00","-0.61","0.54","0.54","-0.41","-1.83"]},{user:"Willie",weeklyPercentageChange:["-0.83","-3.21","0.71","0.00","-1.05","0.35","0.07","0.14","-0.07","-1.45","-3.72"]},{user:"Frank",weeklyPercentageChange:["0.00","0.00","-3.04","0.88","1.37","-0.41","-1.21","2.10","0.00","-0.58","-0.94"]}];

const GetSortOrder = getProp => (a,b) => getProp(a) - getProp(b);
array.sort( GetSortOrder(obj => obj.weeklyPercentageChange[0]) );
document.write("<br><br> Sorted Weekly Percentage Change : <br>");
for (var item in array) {
 document.write("<br>"+array[item].weeklyPercentageChange[0]);
}