LowDB获取具有最高时间戳的对象

Question

      "log": [
        {
          "id": "H1AXR_ns7",
          "batt": 80,
          "lat": "lat here",
          "lon": "lon here",
          "tst": 1540552932
        },
       {
          "id": "H1AXR_ns7",
          "batt": 80,
          "lat": "lat here",
          "lon": "lon here",
          "tst": 1540531234
        },
       {
          "id": "H1AXR_ns7",
          "batt": 80,
          "lat": "lat here",
          "lon": "lon here",
          "tst": 1540511234
       }
  ]

In LowDB, I would like to filter and get the object with the highest tst value for the user with id: H1AXR_ns7 .

I'm not sure how to do this:

I have the following code so far:

  db.get('log')
        .find(id)
        .filter().value()

I know that I have to write an expression in the .filter() , but I have no idea how to write it to get the higest tst for user with id H1AXR_ns7 .

Answer 1

let [highest] = log.sort((a,b)=>a.tst - b.tst)

// highest holds that object now

Answer 2

const id = 'H1AXR_ns7';
const getMax = (accumulator, currentValue) => accumulator.tst < currentValue.tst? currentValue: accumulator;
const latest = log
  .filter(p => p.id === id)
  .reduce(getMax);

Documentation for filter: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

Documentation for reduce: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce