String(const char* char_array) : size(strlen(char_array)), arr_size(size), array(new char[arr_size]) {
    memcpy(array, char_array, size);
  }

  String(const int n, const char c) : size(n), arr_size(size), array(new char [arr_size]) {
    memset(array, c, size);
  }

  String() = default;

  String(const String& old_string) : size(old_string.size), arr_size(size), array(new char[arr_size]) {
    memcpy(array, old_string.array, size);
  }