dart:html

single property

Checks that this iterable has only one element, and returns that element.

Throws a StateError if this is empty or has more than one element.

Source

Touch get single {
  int len = this.length;
  if (len == 1) {
    return _nativeIndexedGetter(0);
  }
  if (len == 0) throw new StateError("No elements");
  throw new StateError("More than one element");
}