Dart: How to get total length of all list values in a list of map?-CodePudding

I have this:

final data = [
    {
      'name': 'Team A',
      'team': ['Klay Lewis', 'Ehsan Woodard', 'River Bains']
    },
    {
      'name': 'Team B',
      'team': ['Toyah Downs', 'Tyla Kane']
    },
    {
      'name': 'Team C',
      'team': [
        'Jacky Chan',
        'Yalor Rowds',
        'Tim Bourla',
        'Levis Strauss',
        'Jane Smow'
      ]
    }
  ];

I want to find the quickest way to get a sum of all team members. In the above example, it would be 3 2 5 = 10 total members.

The real world data will have thousands of teams, so quickest way needed.

CodePudding user response：

fold will get the job done.

final int totalLength = data.fold(0, (sum, obj) => sum   obj['team'].length);

CodePudding user response：

import 'package:collection/collection.dart';

const data = [...];

void main(List<String> args) {
  var members = data.map((e) => (e['team'] as List).length).sum;
  print(members);
}