toupper
From cppreference.com
C
Concurrency support (C11)
Null-terminated byte strings
Functions
Character manipulation
Conversions to and from numeric formats
(C99)(C99)
(C99)(C99)
(C23)(C23)(C23)
String manipulation
String examination
Memory manipulation
Miscellaneous
(C11)(C11)
Defined in header
<ctype.h>
int toupper( int ch );
Converts the given character to uppercase according to the character conversion rules defined by the currently installed C locale.
In the default "C" locale, the following lowercase letters abcdefghijklmnopqrstuvwxyz are replaced with respective uppercase letters ABCDEFGHIJKLMNOPQRSTUVWXYZ.
[edit] Parameters
ch
-
character to be converted. If the value of ch is not representable as unsigned char and does not equal EOF , the behavior is undefined.
[edit] Return value
Uppercase version of ch or unmodified ch if no uppercase version is listed in the current C locale.
[edit] Example
Run this code
#include <ctype.h> #include <limits.h> #include <locale.h> #include <stdio.h> int main(void) { // in the default locale: for (unsigned char l = 0, u; l != UCHAR_MAX ; ++l) if ((u = toupper(l)) != l) printf ("%c%c ", l, u); printf ("\n\n"); unsigned char c = '\xb8'; // the character ž in ISO-8859-15 // but ̧ (cedilla) in ISO-8859-1 setlocale (LC_ALL, "en_US.iso88591"); printf ("in iso8859-1, toupper('0x%x') gives 0x%x\n", c, toupper(c)); setlocale (LC_ALL, "en_US.iso885915"); printf ("in iso8859-15, toupper('0x%x') gives 0x%x\n", c, toupper(c)); }
Possible output:
aA bB cC dD eE fF gG hH iI jJ kK lL mM nN oO pP qQ rR sS tT uU vV wW xX yY zZ
in iso8859-1, toupper('0xb8') gives 0xb8
in iso8859-15, toupper('0xb8') gives 0xb4[edit] References
- C23 standard (ISO/IEC 9899:2024):
- 7.4.2.2 The toupper function (p: TBD)
- C17 standard (ISO/IEC 9899:2018):
- 7.4.2.2 The toupper function (p: 147-148)
- C11 standard (ISO/IEC 9899:2011):
- 7.4.2.2 The toupper function (p: 204)
- C99 standard (ISO/IEC 9899:1999):
- 7.4.2.2 The toupper function (p: 185)
- C89/C90 standard (ISO/IEC 9899:1990):
- 4.3.2.2 The toupper function
[edit] See also
C++ documentation for toupper