std::iswdigit
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | 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.
| 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  | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | 


