sumBy method

int sumBy(
  1. int selector(
    1. E element
    )
)

Returns the sum of selector applied to each element.

Example:

[1, 2, 3].sumBy((n) => n * 10); // 60

Implementation

int sumBy(int Function(E element) selector) {
  int total = 0;
  for (final E element in this) {
    total += selector(element);
  }
  return total;
}