DESCRIPTION

The iswdigit() function is the wide-character equivalent of the isdigit(3) function. It tests whether wc is a wide character belonging to the wide-character class "digit".

The wide-character class "digit" is a subclass of the wide-character class "xdigit", and therefore also a subclass of the wide-character class "alnum", of the wide-character class "graph" and of the wide-character class "print".

Being a subclass of the wide character class "print", the wide-character class "digit" is disjoint from the wide-character class "cntrl".

Being a subclass of the wide-character class "graph", the wide-character class "digit" is disjoint from the wide-character class "space" and its subclass "blank".

Being a subclass of the wide-character class "alnum", the wide-character class "digit" is disjoint from the wide-character class "punct".

The wide-character class "digit" is disjoint from the wide-character class "alpha" and therefore also disjoint from its subclasses "lower", "upper".

The wide-character class "digit" always contains exactly the digits '0' to '9'.

RETURN VALUE

The iswdigit() function returns nonzero if wc is a wide character belonging to the wide-character class "digit". Otherwise it returns zero.

CONFORMING TO

C99.

NOTES

The behavior of iswdigit() depends on the LC_CTYPE category of the current locale.

SEE ALSO

isdigit(3), iswctype(3)