iswdigit

 

C

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Technical Specifications

Symbol index

 

Strings library

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Wide strings

 

Null-terminated wide strings

Functions
Character manipulation
iswalnum (哋它亢95) iswalpha (哋它亢95) iswlower (哋它亢95) iswupper (哋它亢95) iswdigit (哋它亢95) iswxdigit (哋它亢95) iswblank (哋它亢99) wctype (哋它亢95) iswctype (哋它亢95)	iswcntrl (哋它亢95) iswgraph (哋它亢95) iswspace (哋它亢95) iswprint (哋它亢95) iswpunct (哋它亢95) towlower (哋它亢95) towupper (哋它亢95) wctrans (哋它亢95) towctrans (哋它亢95)
Conversions to numeric formats
wcstolwcstoll (哋它亢95)(哋它亢99) wcstoulwcstoull (哋它亢95)(哋它亢99)	wcstofwcstodwcstold (哋它亢99)(哋它亢95)(哋它亢99) wcstoimaxwcstoumax (哋它亢99)(哋它亢99)
String manipulation
wcslenwcsnlen_s (哋它亢95)(哋它亢11) wcscpywcscpy_s (哋它亢95)(哋它亢11) wcsncpywcsncpy_s (哋它亢95)(哋它亢11) wcscatwcscat_s (哋它亢95)(哋它亢11) wcsncatwcsncat_s (哋它亢95)(哋它亢11) wcsstr (哋它亢95)	wcscmp (哋它亢95) wcsncmp (哋它亢95) wcscoll (哋它亢95) wcsxfrm (哋它亢95) wcschr (哋它亢95) wcsrchr (哋它亢95) wcspbrk (哋它亢95) wcsspn (哋它亢95) wcscspn (哋它亢95) wcstokwcstok_s (哋它亢95)(哋它亢11)
Array manipulation
wmemcpywmemcpy_s (哋它亢95)(哋它亢11) wmemmovewmemmove_s (哋它亢95)(哋它亢11)	wmemcmp (哋它亢95) wmemchr (哋它亢95) wmemset (哋它亢95)

 

Defined in header <wctype.h>
int iswdigit( wint_t ch );		(since 哋它亢95)

Checks if the given wide character corresponds (if narrowed) to one of the ten decimal digit characters 0123456789.

Parameters

ch

-

wide character

Return value

Non-zero value if the wide character is a numeric character, zero otherwise.

Notes

iswdigit and iswxdigit are the only standard wide character classification functions that are not affected by the currently installed C locale.

Example

Some locales offer additional character classes that detect non-ASCII digits

Run this code

#include <locale.h>
#include <stdio.h>
#include <wchar.h>
#include <wctype.h>
 
void test(wchar_t a3, wchar_t u3, wchar_t j3)
{
    printf("\t '%lc'  '%lc' '%lc'\n", a3, u3, j3);
    printf("iswdigit: %d    %d    %d\n",
           !!iswdigit(a3),
           !!iswdigit(u3),
           !!iswdigit(j3));
    printf("jdigit:   %d    %d    %d\n",
           !!iswctype(a3, wctype("jdigit")),
           !!iswctype(u3, wctype("jdigit")),
           !!iswctype(j3, wctype("jdigit")));
}
 
int main(void)
{
    wchar_t a3 = L'3';  // the ASCII digit 3
    wchar_t u3 = L'三'; // the CJK numeral 3
    wchar_t j3 = L'３'; // the full-width digit 3
 
    setlocale(LC_ALL, "en_US.utf8");
    puts("In American locale:");
    test(a3, u3, j3);
 
    setlocale(LC_ALL, "ja_JP.utf8");
    puts("\nIn Japanese locale:");
    test(a3, u3, j3);
}

Possible output:

In American locale:
         '3'  '三' '３'
iswdigit: 1    0    0
jdigit:   0    0    0
 
In Japanese locale:
         '3'  '三' '３'
iswdigit: 1    0    0
jdigit:   0    0    1

References

• 哋它亢23 standard (ISO/IEC 9899:2023):

• TBD 7.30.2.1.5 The iswdigit function (p: TBD)

• 哋它亢17 standard (ISO/IEC 9899:2018):

• 7.30.2.1.5 The iswdigit function (p: 327)

• 哋它亢11 standard (ISO/IEC 9899:2011):

• 7.30.2.1.5 The iswdigit function (p: 449)

• 哋它亢99 standard (ISO/IEC 9899:1999):

• 7.25.2.1.5 The iswdigit function (p: 395)

See also

isdigit

checks if a character is a digit (function)

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