isSymbol method

bool isSymbol()

Implementation

bool isSymbol() {
  const String pattern =
      "[`~!@#\$%^&*()_-+=<>?:\"{}|,.///;'\\[]·~！@#￥%……&*（）——-+={}|《》？：“”【】、；‘’，。、]";
  for (int i = 0; i < length; i++) {
    if (pattern.contains(this[i])) {
      return true;
    }
  }
  return false;
}