Defined in header <wctype.h> | ||
|---|---|---|
int iswxdigit( wint_t ch ); | (since C95) |
Checks if the given wide character corresponds (if narrowed) to a hexadecimal numeric character, i.e. one of 0123456789abcdefABCDEF.
| ch | - | wide character |
Non-zero value if the wide character is a hexadecimal numeric character, zero otherwise.
iswdigit and iswxdigit are the only standard wide character classification functions that are not affected by the currently installed C locale.
Some locales offer additional character classes that detect non-ASCII digits
#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("iswxdigit: %d %d %d\n",
!!iswxdigit(a3),
!!iswxdigit(u3),
!!iswxdigit(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'9'; // the ASCII digit 9
wchar_t u3 = L'〩'; // the CJK numeral 9
wchar_t j3 = L'9'; // the full-width digit 9
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:
'9' '〩' '9'
iswxdigit: 1 0 0
jdigit: 0 0 0
In Japanese locale:
'9' '〩' '9'
iswxdigit: 1 0 0
jdigit: 0 0 1| checks if a character is a hexadecimal character (function) |
|
C++ documentation for iswxdigit |
|
| ASCII values | characters |
|
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | GHIJKLMNOPQRSTUVWXYZ | 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 | ghijklmnopqrstuvwxyz | 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 |
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