Array Sort by time hh:mm:ss

Question

I am trying to sort the time. but I am unable to sort by time (hh:mm:ss) format. so i have used moments js. my array sort by time not get sorted. how sort array by using map

Answer 1

The parsedDates map you've created is looking like:

Map {
  [ 'id', 'date' ] => [ 1,  ],
  [ 'id', 'date' ] => [ 2,  ],
  [ 'id', 'date' ] => [ 3,  ],
  [ 'id', 'date' ] => [ 4,  ]
}

And then you try to extract from it with elements like this:

parsedDates.get({ "id": 1, "date": "02:01:02" })

This should not work, because the key in a Map is and Array instance.

Even if you were using an array as a key:

parsedDates.get([ 1, "02:01:02" ])

this still wouldn't work, as this would be a different Object reference. I mean two arrays

a = [ 1, "02:01:02" ]
b = [ 1, "02:01:02" ]

are stored in different places and are different Objects, even though their values are identical.

So, you can modify your solution a bit:

let elements =[
  {
    "id": 1,
    "date": "02:01:02"
  },
  {
    "id": 2,
    "date": "01:01:01"
  },
  {
    "id": 3,
    "date": "03:01:01"
  },
  {
    "id": 4,
    "date": "04:01:01"
  }
 ]; 

let parsedDates = new Map(
      elements.map(e => [e.date, e])
      );

elements = elements.map(x => x.date).sort().map(x => parsedDates.get(x))

console.log(elements)

// [
//   { id: 2, date: '01:01:01' },
//   { id: 1, date: '02:01:02' },
//   { id: 3, date: '03:01:01' },
//   { id: 4, date: '04:01:01' }
// ]