std::iswdigit
From cppreference.com
| Defined in header <cwctype>
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| int iswdigit( wint_t ch ); |
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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 (true) if the wide character is an numeric character, 0 (false) 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 <iostream> #include <cwctype> #include <clocale> void test(wchar_t a3, wchar_t u3, wchar_t j3) { std::wcout << std::boolalpha << " '" << a3 << "' '" << u3 << "' '" << j3 << "'\n" << "iswdigit " << (bool)std::iswdigit(a3) << " " << (bool)std::iswdigit(u3) << " " << (bool)std::iswdigit(j3) << '\n' << "jdigit: " << (bool)std::iswctype(a3, std::wctype("jdigit")) << ' ' << (bool)std::iswctype(u3, std::wctype("jdigit")) << ' ' << (bool)std::iswctype(j3, std::wctype("jdigit")) << '\n'; } int main() { 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 std::setlocale(LC_ALL, "en_US.utf8"); std::wcout << "In american locale:\n"; test(a3, u3, j3); std::wcout << "\nIn japanese locale:\n"; std::setlocale(LC_ALL, "ja_JP.utf8"); test(a3, u3, j3); }
Output:
In american locale:
'3' '三' '3'
iswdigit true false false
jdigit: false false false
In japanese locale:
'3' '三' '3'
iswdigit true false false
jdigit: false false true[edit] See also
| checks if a character is classified as a digit by a locale (function template) | |
| checks if a character is a digit (function) | |
| C documentation for iswdigit
| |
| ASCII values (hex) |
characters |
isdigit |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 - 8 | 0x00-0x08
|
control codes (NUL, etc.)
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 9 | 0x09
|
tab (\t)
|
≠0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 10 - 13 | 0x0A-0x0D
|
whitespaces (\n,\v,\f,\r)
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 14 - 31 | 0x0E-0x1F
|
control codes | ≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 32 | 0x20
|
space | 0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 33 - 47 | 0x21-0x2F
|
!"#$%&'()*+,-./
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 48 - 57 | 0x30-0x39
|
0123456789
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
≠0
|
≠0
|
| 58 - 64 | 0x3a-0x40
|
:;<=>?@
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 65 - 70 | 0x41-0x46
|
ABCDEF
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
≠0
|
| 71 - 90 | 0x47-0x5A
|
GHIJKLMNOPQRSTUVWXYZ
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
| 91 - 96 | 0x5B-0x60
|
[\]^_`
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 97 -102 | 0x61-0x66
|
abcdef
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
≠0
|
| 103-122 | 0x67-0x7A
|
ghijklmnopqrstuvwxyz
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
0
|
| 123-126 | 0x7B-0x7E
|
{|}~
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
| 127 | 0x7F
|
backspace character (DEL)
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|