Latin Capital Letter C
Few uppercase letters pull as much double duty as 'C', which serves simultaneously as the highest single-digit hex letter-digit (representing 12), the namesake of one of computing's most influential programming languages, and a common abbreviation in science and everyday life (Celsius, coulomb, copyright). It sits at ASCII code point 67 (0x43), exactly 32 below its lowercase counterpart 'c' at 99 (0x63), maintaining the single-bit case offset (bit 5) shared by all ASCII A–Z / a–z pairs. In typical English corpora, uppercase 'C' ranks among the more visible consonant capitals thanks to frequent sentence-initial words like 'Can', 'Could', and 'Come'.
Technical Details
Code Example
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// Hex digit to integer conversionchar hex = 'C';int val = (hex >= 'A') ? (hex - 'A' + 10) : (hex - '0');// val == 12
Common Usage
Hexadecimal digit: Uppercase 'C' represents 12 in hex and appears in ubiquitous byte values — 0xCC is the INT3 debug breakpoint opcode on x86 processors, and CSS shorthand colors like #CCC produce a familiar light gray. C-family printf-style formatting with %X outputs uppercase hex digits including 'C'.
Regex and escape-sequence role: In many regex engines, \C matches a single raw byte regardless of encoding — though support is engine-dependent (Perl, Go) and its use is generally discouraged in Unicode-aware contexts. Separately, in C-style strings the lowercase \c has no standard meaning, but some tools use \cX notation for control characters, where the case of the letter following \c can matter depending on the implementation.
Linguistic dual phoneme: In English, 'C' maps to two distinct phonemes — a hard /k/ before 'a', 'o', 'u' (Cat, Core, Cup) and a soft /s/ before 'e', 'i', 'y' (Cent, City, Cycle). This split, inherited from Latin via French, makes 'C' one of the most context-dependent consonants in English spelling and a persistent source of difficulty in text-to-speech systems.
Diacritical variants: Uppercase Ç (cedilla) is a separate functional letter in Turkish, where it represents /tʃ/, and appears as an accented variant in French, Portuguese, and Catalan. Ć (acute) is a distinct letter in Polish, Croatian, and Serbian Latin, while Č (caron) serves the same role in Czech, Slovak, Slovenian, and the Baltic languages — all sorted independently of plain 'C' in their respective alphabets.
Hexadecimal digit: Uppercase 'C' represents 12 in hex and appears in ubiquitous byte values — 0xCC is the INT3 debug breakpoint opcode on x86 processors, and CSS shorthand colors like #CCC produce a familiar light gray. C-family printf-style formatting with %X outputs uppercase hex digits including 'C'.
Regex and escape-sequence role: In many regex engines, \C matches a single raw byte regardless of encoding — though support is engine-dependent (Perl, Go) and its use is generally discouraged in Unicode-aware contexts. Separately, in C-style strings the lowercase \c has no standard meaning, but some tools use \cX notation for control characters, where the case of the letter following \c can matter depending on the implementation.
Linguistic dual phoneme: In English, 'C' maps to two distinct phonemes — a hard /k/ before 'a', 'o', 'u' (Cat, Core, Cup) and a soft /s/ before 'e', 'i', 'y' (Cent, City, Cycle). This split, inherited from Latin via French, makes 'C' one of the most context-dependent consonants in English spelling and a persistent source of difficulty in text-to-speech systems.
Diacritical variants: Uppercase Ç (cedilla) is a separate functional letter in Turkish, where it represents /tʃ/, and appears as an accented variant in French, Portuguese, and Catalan. Ć (acute) is a distinct letter in Polish, Croatian, and Serbian Latin, while Č (caron) serves the same role in Czech, Slovak, Slovenian, and the Baltic languages — all sorted independently of plain 'C' in their respective alphabets.