0xBF

0xBF is a hexadecimal literal commonly used in computing to denote the value 191 in decimal. The 0x prefix signals hex notation in many programming languages, including C, C++, Java, JavaScript, and Python. In binary, 0xBF is represented as 10111111.

In Unicode and character encoding, the code point U+00BF corresponds to the inverted question mark, ¿. In ISO/IEC 8859-1 (Latin-1) and Windows-1252 encodings, the byte 0xBF maps to the same character ¿. In UTF-8, the character U+00BF is encoded using two bytes: 0xC2 0xBF. In HTML, the inverted question mark can be represented as ¿ or as ¿.

Usage and context: the inverted question mark is used as the opening punctuation mark for questions in Spanish and some related languages, appearing at the beginning of interrogative sentences. Its use is dictated by typographic conventions of those languages rather than by the hex value itself; 0xBF is simply one way that the same byte value may be represented in hex form in data and source code.

Notes: different legacy code pages assign different glyphs to the byte value 0xBF outside Latin-1 and Windows-1252, so the interpretation of 0xBF can vary by encoding. When exchanging text across encodings, it is important to ensure consistent character encoding to preserve the intended symbol.