Instance of list flutter

class Sale { int employeeId; double price; Sale[this.employeeId, this.price]; } class Employee { int id; List sales; Employee [this.id, this.sales]; } void main[] { //Create a list of employees and their respective sales List employees = new List[]; employees.add[new Employee[1, [new Sale[1, 100.50], new Sale[1, 300.25]]]]; employees.add[new Employee[2, [new Sale[2, 300.00], new Sale[2, 50.25], new Sale[2, 150.00]]]]; employees.add[new Employee[3, [new Sale[2, 400.00], new Sale[2, 30.75], new Sale[3, 50.00]]]]; //Sort so that the employee with the most sales is on top and so on... employees.sort[[a, b] => [b.sales.fold[0, [prev, element] => prev + element.price]].compareTo[a.sales.fold[0, [prev, element] => prev + element.price]]]; log[employees]; //prints Employee #2, followed by Employee #3, then ending with Employee #1 } void log[var lst] { lst.forEach[[l] => print["Employee #${l.id} has ${l.sales.length} sales totaling ${l.sales.fold[0, [prev, element] => prev + element.price]} dollars!"]]; }

I'm new to flutter. I am getting an error like this, can you help me? I've been stuck in http for json for 5 days, the codes in the source don't work. :[ L It says list not entered but when I enter it does not accept it. I don't know on which line the problem is, but I got a warning like. "The following NoSuchMethodError was thrown building FutureBuilder[dirty, state: _FutureBuilderState#447cc]:" //dosya.co/w8rxecrl44rz/Capture.JPG.html //dosya.co/vk6rd85o7zkx/Capture.JPG2.JPG.html

1. import 'dart:convert';
2.  
3. Post postFromJson[String str] => Post.fromJson[json.decode[str]];
4.  
5. String postToJson[Post data] => json.encode[data.toJson[]];
6.  
7. class Post {
8.   Post[{
9.     required this.userId,
10.     required this.id,
11.     required this.title,
12.     required this.body,
13.   }];
14.  
15.   int userId;
16.   int id;
17.   String title;
18.   String body;
19.  
20.   factory Post.fromJson[Map json] => Post[
21.     userId: json["userId"],
22.     id: json["id"],
23.     title: json["title"],
24.     body: json["body"],
25.   ];
26.  
27.   Map toJson[] => {
28.     "userId": userId,
29.     "id": id,
30.     "title": title,
31.     "body": body,
32.   };
33. }

1. import 'dart:convert';
2.  
3.  
4. import 'package:flutter/material.dart';
5. import 'package:http/http.dart' as http;
6. import 'package:json_http_place_holder/post.dart';
7.  
8. void main[] {
9.   runApp[const MyApp[]];
10. }
11.  
12. class MyApp extends StatefulWidget {
13.   const MyApp[{Key? key}] : super[key: key];
14.  
15.   @override
16.   State createState[] => _MyAppState[];
17. }
18.  
19. class _MyAppState extends State {
20.   Future getData = Future[[] => null];
21.   var con = Uri.parse["//jsonplaceholder.typicode.com/posts"];
22.  
23.   Future fetchPost[] async {
24.     List result = [];
25.     final response = await http.get[con];
26.     if [response.statusCode == 200] {
27.       List listPost = jsonDecode[response.body];
28.       for [int i = 0; i Divider[],
29.                 itemCount: snapshot.data.lenght,
30.               ];
31.             }
32.             //var d =jsonDecode[snapshot.data.body];
33.             return Container[];
34.           },
35.         ],
36.       ],
37.     ];
38.   }
39. }