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Defined in header <wctype.h> | ||
int iswdigit( wint_t ch); | (since C95) | |
Checks if the given wide character corresponds (if narrowed) to one of the ten decimal digit characters0123456789.
Contents |
| ch | - | wide character |
Non-zero value if the wide character is a numeric character, zero otherwise.
iswdigit andiswxdigit 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("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 3wchar_t u3= L'三';// the CJK numeral 3wchar_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 0jdigit: 0 0 0 In Japanese locale: '3' '三' '３'iswdigit: 1 0 0jdigit: 0 0 1
| checks if a character is a digit (function)[edit] | |
C++ documentation foriswdigit | |
| ASCII values | characters | isdigit | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | \173–\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 |
