std::iswalpha

 

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Null-terminated wide strings

Functions
Character classification
iswalnum iswalpha iswlower iswupper iswdigit iswxdigit wctype	iswblank (C++11) iswctype iswcntrl iswgraph iswspace iswprint iswpunct
Character manipulation
towlower towupper	towctrans wctrans
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wcstolwcstoll (C++11)   wcstofwcstodwcstold (C++11)(C++11)	wcstoulwcstoull (C++11) wcstoimaxwcstouimax (C++11)(C++11)
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wcslen wcscmp wcscoll wcsncmp wcschr wcsrchr	wcspbrk wcsspn wcscspn wcsstr wcstok
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wcscpy wcsncpy wcsxfrm	wcscat wcsncat
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wmemcpy wmemmove wmemcmp	wmemchr wmemset
Types wctrans_t wctype_t wint_t	Macros WCHAR_MIN WCHAR_MAX WEOF

 

Defined in header <cwctype>
int iswalpha( std::wint_t ch );

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

If the value of ch is neither representable as a wchar_t nor equal to the value of the macro WEOF, the behavior is undefined.

Parameters

ch

-

wide character

Return value

Non-zero value if the wide character is an alphabetic character, ​0​ otherwise.

Notes

ISO 30112 specifies which Unicode characters are include in POSIX alpha category.

Example

Run this code

#include <clocale>
#include <cwctype>
#include <iostream>
 
int main()
{
    wchar_t c = L'\u0b83'; // Tamil sign Visarga ('ஃ')
 
    std::cout << std::hex << std::showbase << std::boolalpha;
    std::cout << "in the default locale, iswalpha(" << (std::wint_t)c << ") = "
              << (bool)std::iswalpha(c) << '\n';
 
    std::setlocale(LC_ALL, "en_US.utf8");
    std::cout << "in Unicode locale, iswalpha(" << (std::wint_t)c << ") = "
              << (bool)std::iswalpha(c) << '\n';
}

Possible output:

in the default locale, iswalpha(0xb83) = false
in Unicode locale, iswalpha(0xb83) = true

See also

isalpha(std::locale)	checks if a character is classified as alphabetic by a locale (function template)
isalpha	checks if a character is alphabetic (function)
C documentation for iswalpha

ASCII values			characters	iscntrl iswcntrl	isprint iswprint	isspace iswspace	isblank iswblank	isgraph iswgraph	ispunct iswpunct	isalnum iswalnum	isalpha iswalpha	isupper iswupper	islower iswlower	isdigit iswdigit	isxdigit iswxdigit
decimal	hexadecimal	octal
0–8	\x0–\x8	\0–\10	control codes (NUL, etc.)	≠0	0	0	0	0	0	0	0	0	0	0	0
9	\x9	\11	tab (\t)	≠0	0	≠0	≠0	0	0	0	0	0	0	0	0
10–13	\xA–\xD	\12–\15	whitespaces (\n, \v, \f, \r)	≠0	0	≠0	0	0	0	0	0	0	0	0	0
14–31	\xE–\x1F	\16–\37	control codes	≠0	0	0	0	0	0	0	0	0	0	0	0
32	\x20	\40	space	0	≠0	≠0	≠0	0	0	0	0	0	0	0	0
33–47	\x21–\x2F	\41–\57	!"#$%&'()*+,-./	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
48–57	\x30–\x39	\60–\71	0123456789	0	≠0	0	0	≠0	0	≠0	0	0	0	≠0	≠0
58–64	\x3A–\x40	\72–\100	:;<=>?@	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
65–70	\x41–\x46	\101–\106	ABCDEF	0	≠0	0	0	≠0	0	≠0	≠0	≠0	0	0	≠0
71–90	\x47–\x5A	\107–\132	GHIJKLMNOP QRSTUVWXYZ	0	≠0	0	0	≠0	0	≠0	≠0	≠0	0	0	0
91–96	\x5B–\x60	\133–\140	[\]^_`	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
97–102	\x61–\x66	\141–\146	abcdef	0	≠0	0	0	≠0	0	≠0	≠0	0	≠0	0	≠0
103–122	\x67–\x7A	\147–\172	ghijklmnop qrstuvwxyz	0	≠0	0	0	≠0	0	≠0	≠0	0	≠0	0	0
123–126	\x7B–\x7E	\172–\176	{|}~	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
127	\x7F	\177	backspace character (DEL)	≠0	0	0	0	0	0	0	0	0	0	0	0