Test and debug prompt 1:
When the compiler reports a syntax error, the error may not be in the line indicated by the error message, so check if the report is wrong, if not, please check the previous line.
Good programming habits 1:
Check if the expression containing many operators is written, review the operator priority order table. If you are unable to determine the priority order in a complex expression, use the parentheses to force the order!
Good programming habits 2:
Any class name letter is capitalized, which makes the class name easier to distinguish.
