FLutter : The method '[]' was called on null when iterating list - flutter

Question

This is the source code I have till now. Can you tell me what is wrong and why I am getting this error?
Any help would be appreciated. Thanks!
The error is:
error in Data[0] it show Flutter : The method '[]' was called on null when iterating list import 'package:flutter/material.dart';
class MyGetHttpDataState extends State<MyGetHttpData> {
final String url = "*******";
List data, a; int index; // Function to get the JSON data
Future<String> getJSONData() async {
var response = await http.get(url);
print(response.body);
setState(() {
json.decode(response.body);
data = dataConvertedToJSON['data']; index = 0;
});
return "Successfull";
}
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar( title: new Text('List Test'), ),
body: new Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
for (var name in data[0]['INCI']) Text(name)
], ), ), ));
}
#override
void initState() {
super.initState();
this.getJSONData();
}
}

Answer 1

Just change your code to this!
Future<String> getJSONData() async {
var response = await http.get(url);
setState(() {
var dataConvertedToJSON = json.decode(response.body);
data = dataConvertedToJSON['data'];
data = data[0]['INCI'];
});
return "Successfull";
}
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar( title: new Text('List Test'), ),
body: new Center(
child: data != null ? Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
for (var name in data) Text(name)
],
) : new CircularProgressIndicator(),
),
)
);
}