首先，然后使用lodash根据名称对数组进行排序？

Question

我有一些json形式：

data = { 
    "1": {"name": "eve", "type": "sergeant", "age": 22},
    "2": {"name": "bob", "type": "sergeant", "age": 33},
    "3": {"name": "bats", "type": "private", "age": 90},
    "4": {"name": "carol", "type": "captain", "age": 50},
    "5": {"name": "noogle", "type": "sergeant", "age": 34},
    "6": {"name": "good", "type": "sergeant", "age": 47},
    "7": {"name": "alice", "type": "private", "age": 34}
}

如何groupBy它们的type groupBy ，然后在每种类型中按名称将它们按升序排序？

我试图做到这一点：

let grouped = _.groupBy(Object.keys(data), function(id) {
    return data[id].type;
});

这将给我类似的东西：

{
    "sergeant": ["1", "2", "5", "6"],
    "private": ["3", "7"],
    "captain": ["4"]
}

但是当我尝试sortBy它给了我与上面相同的对象：

_.map(Object.keys(grouped), function(type_name) {
    grouped[type_name] = _.sortedBy(grouped[type_name], function(id) {
        return data[id].name;
    });
});

将对象分组在一起后如何排序数组？ 有没有一种方法可以将groupBy和sortBy干净地链接在一起，而不是像上面那样拆分逻辑？

Answer 1

通过使用_.mapValues对每个组进行分组之后，可以使用_.mapValues方法对它们进行_.groupBy 。 只需获取每个值，然后在_.mapValues回调函数中返回其排序版本_.mapValues 。

例：

 data = { "1": {"name": "eve", "type": "sergeant", "age": 22}, "2": {"name": "bob", "type": "sergeant", "age": 33}, "3": {"name": "bats", "type": "private", "age": 90}, "4": {"name": "carol", "type": "captain", "age": 50}, "5": {"name": "noogle", "type": "sergeant", "age": 34}, "6": {"name": "good", "type": "sergeant", "age": 47}, "7": {"name": "alice", "type": "private", "age": 34} } console.log(_.mapValues(_.groupBy(data, "type"), v => _.sortBy(v, "name"))) 

 <script src="https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js"></script> 

或者，如果只希望对键进行分组和排序，或者对键/值进行分组和排序，则可以使用相同的方法，尽管这种方法并不容易：

 data = { "1": {"name": "eve", "type": "sergeant", "age": 22}, "2": {"name": "bob", "type": "sergeant", "age": 33}, "3": {"name": "bats", "type": "private", "age": 90}, "4": {"name": "carol", "type": "captain", "age": 50}, "5": {"name": "noogle", "type": "sergeant", "age": 34}, "6": {"name": "good", "type": "sergeant", "age": 47}, "7": {"name": "alice", "type": "private", "age": 34} } // If all you want are grouped and sorted keys: console.log(_.mapValues(_.groupBy(_.keys(data), k => data[k].type), v => _.sortBy(v, i => data[i].name))) // Or for grouped and sorted keys and values: console.log(_.mapValues(_.groupBy(_.keys(data), k => data[k].type), v => _.sortBy(v, i => data[i].name).map(k => ({[k]: data[k]})))) 

 <script src="https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js"></script>