javascript - Underscore.js - 如何对嵌套的对象数组进行排序

Question

我有以下 JavaScript 对象:

var appointments = [];

appointments.push(
       { id: '101', 
         status: 'accepted',
         appointmentTimes: [ { from: '2016-10-28 12:00', to: '2016-10-28 13:00' } ] },

       { id: '102', 
         status: 'pending', 
         appointmentTimes: [ { from: '2016-10-24 12:00', to: '2016-10-24 13:00' },  
                             { from: '2016-10-24 15:00', to: '2016-10-24 16:00' } ] });

我想使用 from 属性使用 appointmentTimes 数组中的第一项对数组对象进行排序，以便每个对象按日期升序显示。

因此，在上面的示例中，id 为 102 的对象将首先出现在列表中。请注意，appointmentTimes 数组中的每一项都已按升序排列。

我已尝试以下方法，但不起作用:

_.sortBy(appointments, function(appointments) { 
        return appointments.appointmentTimes.from; 
 });

Answer 1

设法修复:

_.sortBy(appointments, function(appointment) { 
    return appointment.appointmentTimes[0].from; 
});