Compare two lists with String data? - arrays

Question

How I can compare two lists with String data?
I need if values in second list match with first, change icon to red, if not match to green.
isEqual ? Colors.red : Colors.green
First list
List<String> pcAll = ['S01', 'S02', 'S03', 'S04', 'S05'];
Second list
List<String> pcBusy = ['S02', 'S03'];
class ComputerGrid extends StatelessWidget {
const ComputerGrid();
#override
Widget build(BuildContext context) {
return GridView.builder(
gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
childAspectRatio: 6 / 3,
crossAxisSpacing: 20,
mainAxisSpacing: 20,
),
itemCount: pcAll.length,
itemBuilder: (BuildContext context, index) {
return GridTile(
child: Container(
color: isEqual() ? Colors.red : Colors.green,
child: Center(
child: Text(
pcAll[index],
),
class _EvrokoStandartScreenState extends State<EvrokoStandartScreen> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(
'ЕВРОКО Стандарт',
),
),
body: ComputerGrid(),

Answer 1

#Чак-Джонс you can compare the list as below.
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<String> pcAll = ['S01', 'S02', 'S03', 'S04', 'S05'];
List<String> pcBusy = ['S02', 'S03'];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: GridView.builder(
gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
childAspectRatio: 6 / 3,
crossAxisSpacing: 20,
mainAxisSpacing: 20,
),
itemCount: pcAll.length,
itemBuilder: (BuildContext context, index) {
return GridTile(
child: Container(
color: pcBusy.contains(pcAll[index]) ? Colors.red : Colors.green,
child: Center(
child: Text(pcAll[index]),
),
),
);
},
),
);
}
}

Answer 2

You can compare two lists in flutter using listEquals method, or create a custom method like this.
bool areListsEqual(var list1, var list2) {
// check if both are lists
if(!(list1 is List && list2 is List)
// check if both have same length
|| list1.length!=list2.length) {
return false;
}
// check if elements are equal
for(int i=0;i<list1.length;i++) {
if(list1[i]!=list2[i]) {
return false;
}
}
return true;
}
void main(){
List list1 = [24, 'Hello', 84];
List list2 = [24, 'Hello', 84];
List list3 = [11, 'Hi', 41];
if(areListsEqual(list1, list2)) {
print('list1 and list2 are equal in value.');
} else {
print('list1 and list2 are not equal in value.');
}
if(areListsEqual(list1, list3)) {
print('list1 and list3 are equal in value.');
} else {
print('list1 and list3 are not equal in value.');
}
}

Answer 3

For listEqual
import 'package:flutter/foundation.dart';
...............
bool isEqual = listEquals(pcAll, pcBusy);
For DeepCollectionEquality
import 'package:collection/collection.dart';
.......
Function deepEq = const DeepCollectionEquality().equals;
bool idDeepEqual = deepEq(pcAll, pcBusy);
Normal hardCoded
List<String> pcAll = [
'S01',
'S02',
'S03',
'S04',
'S05',
'S06',
'S07',
'S09',
'S10'
];
List<String> pcBusy = ['S02', 'S03', 'S05', 'S06', 'S07', 'S08'];
List<String> resultSet1 = [];
pcBusy.forEach((pc) {
if (pcAll.contains(pc)) resultSet1.add(pc);
});
print(resultSet1);
print(resultSet1.length > 0 ? "didnot match" : "match");