C in a Nutshell

Name

iswupper

Synopsis

Ascertains whether a given wide character is an uppercase letter

#include <wctype.h>
intiswupper( wint_t wc );

The iswupper() function is the wide-character version of the isupper() character classification function. It tests whether its character argument is a uppercase letter. If the character is a uppercase letter, isupper() returns a nonzero value (that is, true); if not, the function returns 0 (false).

Which characters are letters and which letters are uppercase both depend on the current locale setting for the category LC_CTYPE, which you can query or change using the setlocale() function. For some locale-specific characters, both iswupper() and iswlower() may return true, or both may return false even though iswalpha() returns true. However, iswupper() is mutually exclusive with iswcntrl(), iswdigit(), iswpunct(), and iswspace() in all locales.

Example

See the example for iswalpha() in this chapter.

See Also

iswlower(), iswalpha(); the corresponding function for byte characters, isupper(); the extensible wide-character classification function, iswctype(); iswalnum(), iswblank(), iswcntrl(), iswdigit(), iswgraph(), iswprint(), iswpunct(), iswspace(), iswxdigit(), setlocale()