This is the response from request.
var response = [{"id":4731},{"id":4566},{"id":4336},{"id":4333},{"id":4172},{"id":4170},{"id":4168},{"id":4166},{"id":4163},{"id":4161}];
How to extract ids and store in List of int using flutter. I have try this code but not working.
Future<List<int>> fetchTopIds() async{
final response = await client.get('$_baseUrl/posts?fields=id');
final ids = json.decode(response.body);
return ids.cast<int>();
}
This should do what you want:
var intIds = ids.map<int>((m) => m['id'] as int).toList();
This is what I did when got "array of object" as response (I know I'm late. But it will help the next guy)
List list = json.decode(response.body);
if (response.body.contains("id")) {
var lst = new List(list.length);
for (int i = 0; i < list.length; i++) {
var idValue = list[i]['id'];
print(idValuee);
}
Here I attached a complete example of converting a list to JSON and then retrieve the List back from that JSON.
import 'dart:convert';
void main() {
List<int> a= [1,2,3]; //List of Integer
var json= jsonEncode(a); //json Encoded to String
print(json.runtimeType.toString());
var dec= jsonDecode(json); //Json Decoded to array of dynamic object
print(dec.runtimeType.toString());
a= (dec as List).map((t)=> t as int).toList(); //dynamic array mapped to integer List
print(a);
}
I found a better and easier way to get required information/ data from JSON Array.
Refer to https://pub.dev/packages/http/example to know more
Code to get a quick starts:
void main(List<String> arguments) async {
var url = 'ENTER YOUR API ENDPOINT';
var response = await http.get(url);
var jsonResponse = convert.jsonDecode(response.body);
var itemCount = jsonResponse['totalItems'];
print('Number of books about http: $itemCount.');
Here 'totalItems' would be your desired key.This will only work if you get a response.statusCode == 200
id field to list of that same ids, not how to access single object property.