How to filter JSON by key value with JavaScript?

To filter JSON by key value with JavaScript, we use the filter method.

For instance, we write

const arr = [
  { time: "2016-07-26 09:02:27", type: "aa" },
  { time: "2016-04-21 20:35:07", type: "ae" },
  { time: "2016-08-20 03:31:57", type: "ar" },
  { time: "2017-01-19 22:58:06", type: "ae" },
  { time: "2016-08-28 10:19:27", type: "ae" },
  { time: "2016-12-06 10:36:22", type: "ar" },
  { time: "2016-07-09 12:14:03", type: "ar" },
  { time: "2016-10-25 05:05:37", type: "ae" },
  { time: "2016-06-05 07:57:18", type: "ae" },
  { time: "2016-10-08 22:03:03", type: "aa" },
  { time: "2016-08-13 21:27:37", type: "ae" },
  { time: "2016-04-09 07:36:16", type: "ar" },
  { time: "2016-12-30 17:20:08", type: "aa" },
  { time: "2016-03-11 17:31:46", type: "aa" },
  { time: "2016-05-04 14:08:25", type: "ar" },
  { time: "2016-11-29 05:21:02", type: "ar" },
  { time: "2016-03-08 05:46:01", type: "ar" },
];
const filtered = arr.filter((a) => a.type == "ar");

to call arr.filter with a callback that checks if thge type property in each object in arr is equal to 'ar'.

An array with the objects in arr with the type property equal to 'ar' is returned.