indexOfFirst method

int indexOfFirst(bool test(E element))

Returns index of the first element passing the given test, or -1 if the collection does not contain such element.

Implementation

int indexOfFirst(bool Function(E element) test) {
  var index = 0;

  for (final element in this) {
    if (test(element)) return index;
    index++;
  }

  return -1;
}