Solution to var problem using a closure in Dart

var_problem_closure_solution.dart

void main() {
  final list = <int>[1, 2, 3, 4, 2, -1, 5];
  final maxValue = 12;
  
  final sum = (){
    var sum = 0;
    for(final val in list) {
      sum += val;
    }
    if(sum > maxValue) {
      sum = maxValue;
    }
    return sum;
  }(); // See the parenthesis to execute the closure/function
  
  /// ... more code that uses `sum` ...
}