std::iswalnum

Header: <cwctype>

Checks if the given wide character is an alphanumeric character, i.e. either a number (0123456789), an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ), a lowercase letter (abcdefghijklmnopqrstuvwxyz) or any alphanumeric character specific to the current locale.

# Declarations

int iswalnum( std::wint_t ch );

# Parameters

ch: wide character

# Return value

Non-zero value if the wide character is an alphanumeric character, zero otherwise.

# Notes

ISO 30112 specifies which Unicode characters are included in the POSIX alnum category.

# Example

#include <clocale>
#include <cwctype>
#include <iostream>
 
int main()
{
    wchar_t c = L'\u13ad'; // the Cherokee letter HA ('Ꭽ')
 
    std::cout << std::hex << std::showbase << std::boolalpha;
    std::cout << "in the default locale, iswalnum(" << (std::wint_t)c << ") = "
              << (bool)std::iswalnum(c) << '\n';
 
    std::setlocale(LC_ALL, "en_US.utf8");
    std::cout << "in Unicode locale, iswalnum(" << (std::wint_t)c << ") = "
              << (bool)std::iswalnum(c) << '\n';
}