javascript - How do I filter and structure this JSON? -

i have array of json objects known events, has fields eventid, eventname , importantly dateofevent.

[{event1}, {event2}, {event3}];

i need iterate on array of events , filter out events on same day. obtain new object this.

"days": [     {         "date": "11-05-2015",         "events": [             {"eventid": 1, ...},             {"eventid": 2, ...},             {"eventid": 3, ...},             {"eventid": 4, ...},         ]     }, 

how can efficiently javascript or angular?

you can create new object dates keys, , values arrays contain events. after have date => events map, convert array in structure want.

assuming original data in variable called "events":

    var events  = [{event 1}, {event 2}...];     var daysmap = {};     var days = [];     events.map(function(event) {         if (days[event.dateofevent] === undefined) {             days[event.dateofevent] = [];         }         days[event.dateofevent].push(event);     });     (var day in daysmap) {         days.push({             date: day,              events: daysmap[day]         });     }