sumBy method

double sumBy(
  1. int? collum(
    1. E? element
    )
)

Sum values collum specified in Iterable

Implementation

double sumBy(int? Function(E? element) collum) {
  double sum = 0;
  this?.forEach((element) {
    int? c = collum(element);
    if (c != null) {
      sum += c;
    }
  });
  return sum;
}