If there is no year element, then the call will return null.

如果没有year元素，则调用返回一个空值。

youdao

That year he was named the nation's No. 1 college football star.

那年他被称为国家的1号大学足球明星。

《柯林斯英汉双解大词典》

No one has any real idea how much the company will make next year.

没有人真正知道公司明年将赚多少钱。

《柯林斯英汉双解大词典》

But he says only one or two students usually choose it each year, and no one did in the graduating class in May.

VOA: special.2009.07.23

And we graduated the same year -- now no one has to say what year that was, even if you know, but we did graduate the same year.

我们同一年毕业的-,当然我不要求你们说出是哪一年，可能有人知道，我们在同一年毕业。

麻省理工公开课 - 化学原理课程节选

So we have--U.S. Government issues bills and that's less than or equal to one year and they pay no interest.

美国政府发行的短期国库券,期限通常小于或等于一年,且不付息

耶鲁公开课 - 金融市场课程节选

Even during the 2000--01 recession their absolute revenues increased: In no year since 2000 have those revenues actually declined.

FORBES: Fact and Comment

And there was no year-over-year change in the churn rate for iPhone customers.

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Since 1990 there was no year in which the Romneys did not owe federal and state income taxes .

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