std::toupper

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Strings library

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

basic_string

basic_string_view (C++17)

char_traits

 

Null-terminated byte strings

Functions
Character manipulation
isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
Conversions to numeric formats
atof atoiatolatoll strtolstrtoll	strtoulstrtoull strtofstrtodstrtold strtoimaxstrtouimax (C++11)(C++11)
String manipulation
strcpy
strncpy
strcat
strncat
strxfrm
String examination
strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
Memory manipulation
memchr
memcmp
memset
memcpy
memmove
Miscellaneous
strerror

 

Defined in header <cctype>
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.

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.

Return value

Converted character or ch if no uppercase version is defined by the current C locale.

Example

Run this code

#include <iostream>
#include <cctype>
#include <clocale>
 
int main()
{
    unsigned char c = '\xb8'; // the character ž in ISO-8859-15
                              // but ¸ (cedilla) in ISO-8859-1 
 
    std::setlocale(LC_ALL, "en_US.iso88591");
    std::cout << std::hex << std::showbase;
    std::cout << "in iso8859-1, toupper('0xb8') gives " << std::toupper(c) << '\n';
    std::setlocale(LC_ALL, "en_US.iso885915");
    std::cout << "in iso8859-15, toupper('0xb8') gives " << std::toupper(c) << '\n';
}

Output:

in iso8859-1, toupper('0xb8') gives 0xb8
in iso8859-15, toupper('0xb8') gives 0xb4

See also

tolower	converts a character to lowercase (function)
toupper(std::locale)	converts a character to uppercase using the ctype facet of a locale (function template)
towupper	converts a wide character to uppercase (function)
C documentation for toupper