Is the "？" character an official character in Japanese syntax?

In English, "?" can end a sentence.
In Japanese, can "？" ever end a sentence?

With regard to the UNICODE standard character blocks:
"。" ---> CJK_SYMBOLS_AND_PUNCTUATION // as expected
"？" ---> HALFWIDTH_AND_FULLWIDTH_FORMS

Is the "？" character an official part of Japanese syntax?
What is "？" called in Japanese?

What is "?" called in Japanese?
What is "？" called in English?

Answer

「？」　全角疑問符/Fullwidth question mark

「?」　半角疑問符/Halfwidth question mark

Question marks are not a part of the traditional Japanese language. However, it is not uncommon to see it used informally or casually nowadays.