Filter an array of objects with latest date if array contains same date with different timestamp in-CodePudding

I have an array of objects and each object has the date. I need to filter the array and get the objects that contains latest date.

[
  {
    "Id": 25,
    "MeasureDate": "2022-08-26T00:01:01.001Z"
  },
  {
    "Id": 26,
    "MeasureDate": "2022-08-26T11:10:01.001Z"
  },
  {
    "Id": 27,
    "MeasureDate": "2022-08-26T16:12:01.001Z"
  },
  {
    "Id": 30,
    "MeasureDate": "2022-08-27T00:08:01.001Z"
  },
  {
    "Id": 31,
    "MeasureDate": "2022-08-27T10:20:10.001Z"
  }
         
]

After filtering the array I need the array should look like below

[
  {
    "Id": 27,
    "MeasureDate": "2022-08-26T16:12:01.001Z"
  },
  {
    "Id": 31,
    "MeasureDate": "2022-08-27T10:20:10.001Z"
  }
]

CodePudding user response：

Here's a solution for your probleme :

function similarDates(obj){ 
    date_obj = new Date(obj.MeasureDate);
    // Getting only the dates with same year, month, day
    let sim_dates = popo.filter((objs) => {
        date =  new Date(objs.MeasureDate)
        return date.toDateString() === date_obj.toDateString()
    });
    // Returning the similare dates
    return sim_dates
}

function filterData(array) {
    result = []

    while(array.length) {
        console.log(array)
        var sameElement =  similarDates(array[0]);

        // removing all the treated elements from the array
        array = array.filter( ( el ) => !sameElement.includes(el));
    
        result.push(sameElement.sort((a, b) => new Date(b.MeasureDate) - new Date(a.MeasureDate)).shift());
    }

    return result;
}

CodePudding user response：

const dateItems = [
  {
    "Id": 25,
    "MeasureDate": "2022-08-26T00:01:01.001Z"
  },
  {
    "Id": 26,
    "MeasureDate": "2022-08-26T11:10:01.001Z"
  },
  {
    "Id": 27,
    "MeasureDate": "2022-08-26T16:12:01.001Z"
  },
  {
    "Id": 30,
    "MeasureDate": "2022-08-27T00:08:01.001Z"
  },
  {
    "Id": 31,
    "MeasureDate": "2022-08-27T10:20:10.001Z"
  }
         
];

// As we loop through your dateItems array we need to keep track of the Latest DateTime for each day
// Probably the easiest way is to create a key on a property for each date and then attach the object
// from your array to that key if it is the first for that date or later than an existing one.
const latestDateTimesByDate = {};

dateItems.forEach( di => {

  // Use the date part of the date time as a key/ property name on the latestDateTimesByDate object
  let dateKey = di.MeasureDate.substring(0, 10);
  
  // If that date key doesnt exist or the current MeasureDate  is gretaer than the recorded one
  if( !latestDateTimesByDate[dateKey] || di.MeasureDate > latestDateTimesByDate[dateKey].MeasureDate) {
    latestDateTimesByDate[dateKey] = di;
  }

});

// if you need it as an array then add each of the date properties to an element of an array
const finalArray = [];
Object.keys(latestDateTimesByDate).forEach( key => finalArray.push(latestDateTimesByDate[key]));