在执行了一些underscore.js操作(_.map
,_.each
,_.pluck
和_.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"
}]
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