std::iswdigit
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C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Text processing library
Regular expressions library (C++11)
Formatting library (C++20)
Null-terminated wide strings
Character manipulation
Conversions to numeric formats
String manipulation
String examination
Array manipulation
(C++11)
(C++11)(C++11)
Defined in header
<cwctype>
int iswdigit( wint_t ch );
Checks if the given wide character corresponds (if narrowed) to one of the ten decimal digit characters 0123456789.
If the value of ch is neither representable as a wchar_t nor equal to the value of the macro WEOF, the behavior is undefined.
Contents
[edit] Parameters
ch
-
wide character
[edit] Return value
Non-zero value if the wide character is a numeric character, zero otherwise.
[edit] Notes
std::iswdigit
and std::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 <clocale> #include <cwctype> #include <iostream> void test(wchar_t a3, wchar_t u3, wchar_t j3) { std::wcout << std::boolalpha << "\t '" << 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 full-width 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); }
Possible 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
C documentation for iswdigit
ASCII values | characters |
isdigit |
|||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
decimal | hexadecimal | octal | |||||||||||||
0–8 | \x0 –\x8
|
0円 –10円
|
control codes (NUL , etc.)
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
9 | \x9
|
11円
|
tab (\t )
|
≠0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
10–13 | \xA –\xD
|
12円 –15円
|
whitespaces (\n , \v , \f , \r )
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
14–31 | \xE –\x1F
|
16円 –37円
|
control codes | ≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
32 | \x20
|
40円
|
space | 0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
33–47 | \x21 –\x2F
|
41円 –57円
|
!"#$%&'()*+,-./
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
48–57 | \x30 –\x39
|
60円 –71円
|
0123456789
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
≠0
|
≠0
|
58–64 | \x3A –\x40
|
72円 –100円
|
:;<=>?@
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
65–70 | \x41 –\x46
|
101円 –106円
|
ABCDEF
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
≠0
|
71–90 | \x47 –\x5A
|
107円 –132円
|
GHIJKLMNOP QRSTUVWXYZ
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
91–96 | \x5B –\x60
|
133円 –140円
|
[\]^_`
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
97–102 | \x61 –\x66
|
141円 –146円
|
abcdef
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
≠0
|
103–122 | \x67 –\x7A
|
147円 –172円
|
ghijklmnop qrstuvwxyz
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
0
|
123–126 | \x7B –\x7E
|
172円 –176円
|
{|}~
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
127 | \x7F
|
177円
|
backspace character (DEL )
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|