在执行了一些underscore.js操作(_.map_.each_.pluck_.flatten)之后,我得到了一个看起来像这样的对象数组:

var userArray = [
  {id: 123456, username: "bill123", group: "ONE"},
  {id: 123457, username: "joe123", group: "TWO"},
  {id: 123457, username: "joe123", group: "TWO"},
  {id: 123458, username: "jim123", group: "ONE"}
]


我需要创建一个新数组,删除重复项,并计算对象出现在数组中的次数。我可以通过两个单独的underscore.js函数获得所需的结果,但是在合并两个结果时遇到了麻烦。

工作功能如下:

var uniqUsers = _.uniq(taggedUsers, false, function(user) {
  return user.id
});
  //returns array of unique objects in the same format as above
  //[{id: 123457, username: "joe123", group: "TWO"},...]

var userCounts = _.countBy(taggedUsers, "id");
  //returns the count for each user in the userArray in a single object
  //{123456: 1, 123457: 2, 123458: 1}




返回这样的对象数组的最佳方法是:

{id: 123457, username: "joe123", group: "TWO", count: 2}


我可以向_.countBy函数添加其他字段吗?还是我需要对_.map做些什么?

任何帮助将不胜感激 !谢谢

最佳答案

您可以在map上使用userCounts创建一个新数组,然后可以对其进行排序。

var userArray = [
  {id: 123456, username: "bill123", group: "ONE"},
  {id: 123457, username: "joe123", group: "TWO"},
  {id: 123457, username: "joe123", group: "TWO"},
  {id: 123458, username: "jim123", group: "ONE"}
];

var userCounts = _.countBy(userArray, "id");

var result = _.sortBy(_.map(userCounts, function(count, id) {
  var user = _.findWhere(userArray, {id: Number(id)});
  return _.extend({}, user, {count: count});
}), 'count');

console.log(result);


结果:

[[object Object] {
  count: 1,
  group: "ONE",
  id: 123456,
  username: "bill123"
}, [object Object] {
  count: 1,
  group: "ONE",
  id: 123458,
  username: "jim123"
}, [object Object] {
  count: 2,
  group: "TWO",
  id: 123457,
  username: "joe123"
}]


JSBin

10-05 20:40
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