Async and Practical

JSON Parse

Sum Values

jsonDecode from dart:convert parses JSON text into Dart maps and lists. Casting recovers concrete types.

Program

Play the program to parse a small JSON map and total its values.

json_parse.dart 
import 'dart:convert';

void main() {
  var raw = '{"a": 10, "b": 20, "c": 30}';
  var data = jsonDecode(raw) as Map<String, dynamic>;
  var total = data.values.cast<int>().reduce((a, b) => a + b);
  print('total=$total');
}
dart:convert `import 'dart:convert'` exposes `jsonDecode` and `jsonEncode`.
jsonDecode Parses JSON text into `Map`, `List`, or scalar values.
cast and reduce `values.cast<int>().reduce(...)` sums the integers.