如何将数组中的元素分组为满足特定条件的对象，并将其推送到新数组中

Question

我有以下数组：

"devices": [
    {
      "_id": "HP Printer",
      "count": 1
    },
    {
      "_id": "55UA8990",
      "count": 1
    },
    {
      "_id": "Mac OS X 10.5",
      "count": 1
    },
    {
      "_id": "Nokia",
      "count": 4
    },
    {
      "_id": "Ubuntu Linux",
      "count": 3
    },
    {
      "_id": "LG handset",
      "count": 1
    },
    {
      "_id": "Samsung Home Audio/Video equipment",
      "count": 1
    },
    {
      "_id": "Generic Linux",
      "count": 1
    },
    {
      "_id": "Sony handset",
      "count": 1
    },
    {
      "_id": "Mac OS X 10.8",
      "count": 12
    },
    {
      "_id": "Linux Handheld",
      "count": 1
    },
    {
      "_id": "Symbian OS",
      "count": 15
    },
    {
      "_id": "RIM BlackBerry",
      "count": 28
    },
    {
      "_id": "Apple iPod",
      "count": 1
    },
    {
      "_id": "LG BL40",
      "count": 1
    },
    {
      "_id": "Slingbox",
      "count": 67
    },
    {
      "_id": "Windows XP",
      "count": 60
    },
    {
      "_id": "BlackBerry",
      "count": 51
    },
    {
      "_id": "Chrome OS",
      "count": 7
    },
    {
      "_id": "Eye-Fi Wireless Memory Card",
      "count": 6
    },
    {
      "_id": "Mac OS X 10.9",
      "count": 62
    },
    {
      "_id": "Mac OS X 10.10",
      "count": 215
    },
    {
      "_id": "Windows Vista",
      "count": 4
    },
    {
      "_id": "Windows Mobile OS",
      "count": 213
    },
    {
      "_id": "Windows 7/Vista",
      "count": 394
    },
    {
      "_id": "Mac OS X 10.11",
      "count": 303
    },
    {
      "_id": "Samsung TV",
      "count": 1
    },
    {
      "_id": "PlayStation Portable",
      "count": 1
    },
    {
      "_id": "Mac OS X",
      "count": 755
    },
    {
      "_id": "Windows 7",
      "count": 612
    },
    {
      "_id": "Apple iPad",
      "count": 2597
    },
    {
      "_id": "Ellipsis 8",
      "count": 193
    },
    {
      "_id": "Mac OS X 10.12",
      "count": 550
    },
    {
      "_id": "Nexus",
      "count": 4657
    },
    {
      "_id": "Windows 10",
      "count": 772
    },
    {
      "_id": "Windows 8",
      "count": 1191
    },
    {
      "_id": "Xbox 360",
      "count": 39
    },
    {
      "_id": "Mac OS X 10.6",
      "count": 5
    },
    {
      "_id": "Apple iPhone",
      "count": 41039
    },
    {
      "_id": "iOS",
      "count": 25725
    },
    {
      "_id": "Debian-based Linux",
      "count": 9
    },
    {
      "_id": null,
      "count": 5291
    },
    {
      "_id": "Mac OS X 10.7",
      "count": 16
    },
    {
      "_id": "Belkin Wireless Router",
      "count": 1
    },
    {
      "_id": "Windows",
      "count": 1002
    },
    {
      "_id": "Android",
      "count": 51314
    }
  ]

我试图将_id对应于相同os的所有值分组，并从每个元素中添加count，这样我就可以得到如下内容：

[
   {
    "label": "Windows",
    "value": "9999"
   },
   {
    "label": "Android",
    "value": "8888"
   },
   {
    "label": "iOS",
    "value": "7777"
   },
   {
    "label": "Macos",
    "value": "10000"
   },
   {
    "label": "Other",
    "value": "5000"
   }
]

我在这里完全迷路了，我非常感谢你的帮助和指导。

Answer 1

在您的场景中使用Array.prototype.reduce和String.prototype.match。希望这能有所帮助。

​

var input = {"devices":[{"_id":"HP Printer","count":1},{"_id":"55UA8990","count":1},{"_id":"Mac OS X 10.5","count":1},{"_id":"Nokia","count":4},{"_id":"Ubuntu Linux","count":3},{"_id":"LG handset","count":1},{"_id":"Samsung Home Audio/Video equipment","count":1},{"_id":"Generic Linux","count":1},{"_id":"Sony handset","count":1},{"_id":"Mac OS X 10.8","count":12},{"_id":"Linux Handheld","count":1},{"_id":"Symbian OS","count":15},{"_id":"RIM BlackBerry","count":28},{"_id":"Apple iPod","count":1},{"_id":"LG BL40","count":1},{"_id":"Slingbox","count":67},{"_id":"Windows XP","count":60},{"_id":"BlackBerry","count":51},{"_id":"Chrome OS","count":7},{"_id":"Eye-Fi Wireless Memory Card","count":6},{"_id":"Mac OS X 10.9","count":62},{"_id":"Mac OS X 10.10","count":215},{"_id":"Windows Vista","count":4},{"_id":"Windows Mobile OS","count":213},{"_id":"Windows 7/Vista","count":394},{"_id":"Mac OS X 10.11","count":303},{"_id":"Samsung TV","count":1},{"_id":"PlayStation Portable","count":1},{"_id":"Mac OS X","count":755},{"_id":"Windows 7","count":612},{"_id":"Apple iPad","count":2597},{"_id":"Ellipsis 8","count":193},{"_id":"Mac OS X 10.12","count":550},{"_id":"Nexus","count":4657},{"_id":"Windows 10","count":772},{"_id":"Windows 8","count":1191},{"_id":"Xbox 360","count":39},{"_id":"Mac OS X 10.6","count":5},{"_id":"Apple iPhone","count":41039},{"_id":"iOS","count":25725},{"_id":"Debian-based Linux","count":9},{"_id":null,"count":5291},{"_id":"Mac OS X 10.7","count":16},{"_id":"Belkin Wireless Router","count":1},{"_id":"Windows","count":1002},{"_id":"Android","count":51314}]};

var output = input.devices.reduce(function(a, b) {
  var match = b._id?b._id.match(/(Mac|Windows|Android|iOS)/):null;
  match = match ? match[0] : 'Others';
  a[match] = (a[match] || 0) + b.count;
  return a;
}, {});

output = Object.keys(output).map(function(k){
  return {
    label: k,
    value: output[k]
  };
});
console.log(output);

​

Answer 2

• 创建一个regex值数组，每个值都匹配特定的操作系统，如.*windows.*。
• 迭代数据数组，尝试将每个条目的_id与regex匹配。
• 如果匹配，则在输出数组中向value添加计数值。如果它不是一个匹配，那么添加到“其他”。

你怎么做是由你自己决定的，这只是一个一般性的想法。

Answer 3

你可以这样做：

var results = [];
devices.forEach(function(d) {
   if(results.length === 0){ //shortcut for the first element
     results.push({label:d._id, value: d.count});
   } else {
       var found = false;
       for(var j =0; j < results.length; j++){
         var i = results[j];
         if(i.label === d._id){
          found = true;
          i.value += d.count;
          results[j] = i;
         }
       });
       if(!found) {
            results.push({label:d._id, value: d.count});
       }
   }
});
return results;

这将迭代设备数组，并在数组中找到匹配的元素，并将计数添加到结果数组中该项的值中。如果找不到该项，或者它是第一个项，则会将一个新对象推送到结果数组。