std::iswdigit - cppreference.com (original) (raw)

| | | | | --------------------------- | | | | 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.

[edit] Parameters

[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

#include #include #include   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