iswdigit
From cppreference.com
Defined in header <wctype.h>
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int iswdigit( wint_t ch ); |
(since C95) | |
Checks if the given wide character corresponds (if narrowed) to one of the ten decimal digit characters 0123456789.
Contents |
[edit] Parameters
ch | - | wide character |
[edit] Return value
Non-zero value if the wide character is an numeric character, zero otherwise.
[edit] Notes
iswdigit
and iswxdigit are the only standard wide character classification functions that are not affected by the currently installed C locale.
[edit] Example
Some locales offer additional character classes that detect non-ASCII digits
Run this code
#include <stdio.h> #include <wctype.h> #include <wchar.h> #include <locale.h> void test(wchar_t a3, wchar_t u3, wchar_t j3) { printf(" '%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 fullwidth 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); }
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
[edit] References
- C11 standard (ISO/IEC 9899:2011):
- 7.30.2.1.5 The iswdigit function (p: 449)
- C99 standard (ISO/IEC 9899:1999):
- 7.25.2.1.5 The iswdigit function (p: 395)
[edit] See also
checks if a character is a digit (function) | |
C++ documentation for iswdigit
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ASCII values (hex) |
characters |
isdigit |
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0 - 8 | 0x00-0x08
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control codes (NUL , etc.)
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≠0
|
0
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0
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0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
9 | 0x09
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tab (\t )
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≠0
|
0
|
≠0
|
≠0
|
0
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0
|
0
|
0
|
0
|
0
|
0
|
0
|
10 - 13 | 0x0A-0x0D
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whitespaces (\n ,\v ,\f ,\r )
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≠0
|
0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
14 - 31 | 0x0E-0x1F
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control codes | ≠0
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0
|
0
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0
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0
|
0
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0
|
0
|
0
|
0
|
0
|
0
|
32 | 0x20
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space | 0
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≠0
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≠0
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≠0
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0
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0
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0
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0
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0
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0
|
0
|
0
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33 - 47 | 0x21-0x2F
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!"#$%&'()*+,-./
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0
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≠0
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0
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0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
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48 - 57 | 0x30-0x39
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0123456789
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0
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≠0
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0
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0
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≠0
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0
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≠0
|
0
|
0
|
0
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≠0
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≠0
|
58 - 64 | 0x3a-0x40
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:;<=>?@
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0
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≠0
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0
|
0
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≠0
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≠0
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0
|
0
|
0
|
0
|
0
|
0
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65 - 70 | 0x41-0x46
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ABCDEF
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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≠0
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0
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0
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≠0
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71 - 90 | 0x47-0x5A
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GHIJKLMNOPQRSTUVWXYZ
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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≠0
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0
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0
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0
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91 - 96 | 0x5B-0x60
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[\]^_`
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0
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≠0
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0
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0
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≠0
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≠0
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0
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0
|
0
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0
|
0
|
0
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97 -102 | 0x61-0x66
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abcdef
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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0
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≠0
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0
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≠0
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103-122 | 0x67-0x7A
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ghijklmnopqrstuvwxyz
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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0
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≠0
|
0
|
0
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123-126 | 0x7B-0x7E
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{|}~
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0
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≠0
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0
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0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
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127 | 0x7F
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backspace character (DEL )
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≠0
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0
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0
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0
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0
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0
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0
|
0
|
0
|
0
|
0
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0
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