sumBy<R extends num> method

R sumBy<R extends num>(
  1. R selector(
    1. T
    )
)

Returns the sum of all values produced by selector function applied to each element in the collection.

Implementation

R sumBy<R extends num>(R Function(T) selector) {
  var sum = R == double ? 0.0 : 0;
  for (final element in iter) {
    sum += selector(element);
  }
  return sum as R;
}