LateInitializationError: Field 'check' has not been initialized - flutter

Question

I'm trying to Use data that I fetched from database and i got an error : "LateInitializationError: Field 'check' has not been initialized. "
, i tried to remove the late word and adding " ? " and it gives another error "Expected a value of type 'num', but got one of type 'Null'
"
class _letterssState extends State<letterss> {
late var check;
Future getData() async{
var url = 'http://ip/getSpell.php';
http.Response response = await http.get(Uri.parse(url));
var data = jsonDecode(response.body);
check=data;
print(data.toString());
}
bool searchRes (String s){
int x=0;
for ( var i=0 ; i<check.length;i++ )
{
if (check[i]['letter']==s){
x=i;
}
}
if (check[x]['result']=='true')
{
return true;
}
else
{
return true;
}
}
initState()
{
getData();
}

Answer 1

It will take some frame to get data from getData future method and assigning on check.
It would better to use FutureBuilder for future methods. Follow this doc example
Future<List<yourDataType>?> getData() async {
var url = 'http://ip/getSpell.php';
http.Response response = await http.get(Uri.parse(url));
var data = jsonDecode(response.body);
return data;
}
late final future = getData();
#override
Widget build(BuildContext context) {
return FutureBuilder<List<YourDataType>?>(
future: future,
builder: (context, snapshot) {
if (snapshot.hasData) {
//todo:
}
return CircularProgressIndicator();
},
);
}