sum<T extends num> method

T sum<T extends num>(
  1. T f(
    1. E element
    )
)

求和

Implementation

T sum<T extends num>(T Function(E element) f) {
  if (isNullOrEmpty()) {
    return 0 as T;
  }
  T total = (T == int ? 0 : 0.0) as T;
  for (var i = 0; i < this!.length; i++) {
    total = (total + f(this![i])) as T;
  }
  return total;
}