Underscore.js - 如何对嵌套的对象数组进行排序

Question

I have the following javascript object:

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' } ] });

I want to sort the array objects using the first item in the appointmentTimes array using the from property so that each object appears in ascending date order.

So in the above example, object with id 102 would appear first in the list. Note each item in appointmentTimes array is already in ascending order.

I've tried the following but it doesnt work:

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

Answer 1

Managed to fix:

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