groupby-list-of-objects

GroupByListOfObjectsInDart.md

Grouping List of Objects

This dart pad is a sample code to group List of Objects based on an attribute of the list.

main.dart

import "package:collection/collection.dart";
import 'package:intl/intl.dart';

class PayRecord {
  String name;
  String type;
  String reason;
  double amount;
  DateTime date;

  PayRecord(this.name, this.type, this.reason, this.amount, this.date);

  @override
  String toString() {
    return '{$name, $type, $reason, $amount}';
  }
}

Map<String, List<PayRecord>> groupPayRecordByDate(List<PayRecord> payRecord) {
  final groups = groupBy(payRecord, (PayRecord pr) {
    return DateFormat.yMd().format(pr.date);
  });

  return groups;
}

void main() {
  var objData = [
    PayRecord("Srinu", "owes you", "", 24.0, DateTime(2023, 1, 10)),
    PayRecord("Srinu", "you owe", "", 24.0, DateTime(2023, 1, 10)),
    PayRecord("Vivek", "you owe", "", 24.0, DateTime(2023, 1, 11)),
    PayRecord("Shobhit", "owes you", "", 24.0, DateTime(2023, 1, 11)),
  ];

  var newObjData = groupPayRecordByDate(objData);
  print(newObjData);
//   print(newObjData["2023-01-10 00:00:00.000"]?.first.amount);
}