Protected reserved keywords cannot be used as identifiers.

受保护的保留字不能用作标识符。

youdao

Standard exception names are built-in identifiers (not reserved keywords).

标准异常名是内置的标识(没有保留关键字)。

youdao

Note, NULLID, NULLIDR1 and NULLIDRA are reserved keywords, and cannot be used for other purposes.

注意，NULLID、NULLIDR1和NULLIDRA都是保留关键词，它们不能够用作其他用途。

youdao