average method Null safety

double average()

Returns an average value of elements in the collection, double.nan if empty.

Implementation

double average() {
  final self = this;
  var count = 0;
  num sum = 0;
  if (self != null) {
    for (final e in self) {
      sum += e;
      count++;
    }
  }
  return count > 0 ? sum / count : double.nan;
}