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Mapping Multiple Lists in Flutter/Dart?


Mapping Multiple Lists in Flutter/Dart?

By : András Rusznyák
Date : November 21 2020, 03:00 PM
Hope that helps You can use List.sort() for that purpose, I have created a custom example where I hard coded 3 instances of your Videos class, and then added them in my build method in a List in ascending order. Using List.sort() and compareTo, I was able to rearrange them in an descending order.
code :
List<Videos> myList = [_firstVideos, _secondVideos, _thirdVideos];
sort() {
      for (var video in myList) {
        print(video.rank); ///prints 1 2 3 
      }
      myList.sort((y, x) => x.rank.compareTo(y.rank));

      for (var video in myList) {
        print(video.rank);  ///prints 3 2 1
      }
    }
import 'package:flutter/material.dart';


    void main(){
      runApp(new MaterialApp(home: new MyApp(),));
    }

    class MyApp extends StatelessWidget {

      Videos _firstVideos = new Videos(
        videoId: "0001",
        rank: 1,
        title: "My First Video",
        imageString: "My First Image",
      );
      Videos _secondVideos = new Videos(
        videoId: "0002",
        rank: 2,
        title: "My Seocnd Video",
        imageString: "My Second Image",
      );

      Videos _thirdVideos = new Videos(
        videoId: "0003",
        rank: 3,
        title: "My Third Video",
        imageString: "My Third Image",
      );

      @override
      Widget build(BuildContext context) {
        List<Videos> myList = [_firstVideos,_secondVideos,_thirdVideos];
        sort()
        {
          myList.sort((y,x)=>x.rank.compareTo(y.rank));

        print(myList[0].title);
        }
        return new Scaffold(
          body: new Center(
            child: new FlatButton(onPressed: sort, child: new Text("Sort")),
          ),
        );
      }
    }


    class Videos{
      String videoId;
      int rank;
      String title;
      String imageString;

      Videos({this.videoId, this.rank, this.title, this.imageString});
    }


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Dart Flutter : How to use multiple statements in ternary inside a flutter widget

Dart Flutter : How to use multiple statements in ternary inside a flutter widget


By : icelobber
Date : March 29 2020, 07:55 AM
This might help you Is it possible to write such a line, and within this line I want change a variable value? , Not sure what you expect the code to do exactly but my guess
code :
opacity: condition == true ? (){ stringName = 'Steve'; return 0; }() : 0;
Convert two lists in to dictionary in dart programming flutter

Convert two lists in to dictionary in dart programming flutter


By : user3079649
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , You could do something like this, although I'm sure there are cleaner ways out there:
code :
var z = new Map<String, String>(); 

for( var i = 0; i <= x.length; i++ ) { 
  z[x[i]] = y[i]; 
} 
Get difference of lists flutter dart

Get difference of lists flutter dart


By : quraish
Date : March 29 2020, 07:55 AM
Does that help I have two lists [1,2,3,4,5,6,7] and [3,5,6,7,9,10]. I want to get the difference of the first list and the second list. , you can do something like this:
code :
List<double> first = [1,2,3,4,5,6,7];
List<double> second = [3,5,6,7,9,10];
List<double> output = [];

first.forEach((element) {
    if(!second.contains(element)){
    output.add(element);
}
});

//at this point, output list should have the answer
List<double> first = [1,2,3,4,5,6,7];
List<double> second = [3,5,6,7,9,10];
List<double> output = first.where((element) => !second.contains(element));
Flutter: I need a hand with dart obj and mapping

Flutter: I need a hand with dart obj and mapping


By : user3332565
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I'm kind of starting out with Dart and Flutter. I already got a bit the hang of it. But one thing is blocking me. And it's confusing my mind a little. , Instead of this:
code :
children: <Widget>[
      ...(resp.groups as List<Group>).map((group) {
        //print(group);
        return  GroupBody();
      })
children: resp.groups.values.map((group) {
        //print(group);
        return  GroupBody();
      }).toList()
group['members']['1']
Flutter: I have changed the Dart entrypoint to Login.dart , while building apks error shows that lib\main.dart not found

Flutter: I have changed the Dart entrypoint to Login.dart , while building apks error shows that lib\main.dart not found


By : user3371059
Date : March 29 2020, 07:55 AM
Any of those help C:\flutter\flutter_windows_v1.9.1+hotfix.2-stable\flutter\bin\flutter.bat --no-color build apk Target file "lib\main.dart" not found. Process finished with exit code 1 , You can set an entry point like this:
code :
flutter run --target=lib/Login.dart
flutter build apk --target=lib/Login.dart
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