toupper
From cppreference.com
Defined in header <ctype.h>
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int toupper( int ch ); |
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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
.
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.
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Return value
Uppercase version of ch
or unmodified ch
if no uppercase version is listed in the current C locale.
Example
Run this code
#include <stdio.h> #include <ctype.h> #include <locale.h> #include <limits.h> int main(void) { /* In the default locale: */ unsigned char u; for (unsigned char l=0; l<UCHAR_MAX; l++) { u = toupper(l); if (l!=u) printf("%c%c ", l,u); } printf("\n\n"); unsigned char c = '\xb8'; // the character in ISO-8859-15 // but (acute accent) in ISO-8859-1 unsigned char c2 = c; // for printing setlocale(LC_ALL, "en_US.iso88591"); printf("in iso8859-1, toupper('0x%x') gives 0x%x\n", c2, toupper(c)); setlocale(LC_ALL, "en_US.iso885915"); printf("in iso8859-15, toupper('0x%x') gives 0x%x\n", c2, toupper(c)); }
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
References
- C11 standard (ISO/IEC 9899:2011):
- 7.4.2.2 The toupper function (p: 204)