code: public static boolean hasExpressionOperators(final String str) {
  
      boolean result = false;
  
      for (final char chr : OPERATOR_FIRST_CHARS) {
        if (str.indexOf(chr) >= 0) {
          result = true;
          break;
        }
      }
      return result;
    }
docs: Check that a string has a char of operators.
  
  @param str a string to be checked, must not be null
  @return true if the string contains a char of an operator, false otherwise