Latin Small Letter B
The second letter of the Latin alphabet and a consonant appearing in roughly 1.5% of characters in typical English text. In computing, 'b' is a hexadecimal digit representing the value 11 and serves as the conventional marker for binary literal notation (0b) in several programming languages. Its ASCII code point is 98 (0x62), sitting 32 above uppercase 'B' at 66 (0x42) — the same single-bit case offset (bit 5) shared by all ASCII A–Z / a–z letter pairs.
Technical Details
Code Example
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// Binary literal with 0b prefix (C++14, GCC extension)int flags = 0b1010; // 10 in decimalint mask = 0b11110000; // Extract high nibble
Common Usage
Hexadecimal notation: Lowercase 'b' represents the value 11 in hex, appearing frequently in CSS color definitions (#0b3d91), cryptographic digests, UUID strings, and raw memory dumps.
Binary literal prefix: Languages including Python, Rust, C++14, Java, and JavaScript use the 0b prefix to denote binary integer literals (e.g., 0b1010 for decimal 10), with 'b' chosen as a mnemonic for 'binary'.
Escape sequence ambiguity: The sequence \b behaves differently depending on context — in C-style strings it typically produces a backspace character (0x08), while in most regex engines it matches a zero-width word boundary. This dual meaning is a common source of bugs when patterns are built from string literals.
Diacritical variants: Several orthographies extend 'b' with diacritics — ḅ (dot below, used in Yoruba and IAST transliteration), ḃ (dot above, used in Old Irish), and ƀ (stroke, used in some African languages) — though its modified-glyph family is considerably smaller than that of vowel letters.
Hexadecimal notation: Lowercase 'b' represents the value 11 in hex, appearing frequently in CSS color definitions (#0b3d91), cryptographic digests, UUID strings, and raw memory dumps.
Binary literal prefix: Languages including Python, Rust, C++14, Java, and JavaScript use the 0b prefix to denote binary integer literals (e.g., 0b1010 for decimal 10), with 'b' chosen as a mnemonic for 'binary'.
Escape sequence ambiguity: The sequence \b behaves differently depending on context — in C-style strings it typically produces a backspace character (0x08), while in most regex engines it matches a zero-width word boundary. This dual meaning is a common source of bugs when patterns are built from string literals.
Diacritical variants: Several orthographies extend 'b' with diacritics — ḅ (dot below, used in Yoruba and IAST transliteration), ḃ (dot above, used in Old Irish), and ƀ (stroke, used in some African languages) — though its modified-glyph family is considerably smaller than that of vowel letters.