C in a Nutshell

Name

iswctype

Synopsis

Ascertains whether a given wide character fits a given description

#include <wctype.h>
intiswctype( wint_t wc, wctype_t description );

The iswctype() function tests whether the wide character passed as its first argument falls in the category indicated by the second argument. The value of the second argument, with the special-purpose type wctype_t, is obtained by calling the function wctype() with a string argument that names a property of characters in the current locale. In the default locale, C, characters can have the properties listed in Table 17-4.

Table 17-4. Wide character properties

Character property	iswctype() call	Equivalent single function call
“alnum”	iswctype(wc, wctype(“alnum”))	isalnum(wc)
“alpha”	iswctype(wc, wctype(“alpha”))	isalpha(wc)
“blank”	iswctype(wc, wctype(“blank”))	isblank(wc)
“cntrl”	iswctype(wc, wctype(“cntrl”))	iscntrl(wc)
“digit”	iswctype(wc, wctype(“digit”))	isdigit(wc)
“graph”	iswctype(wc, wctype(“graph”))	isgraph(wc)
“lower”	iswctype(wc, wctype(“lower”))	islower(wc)
“print”	iswctype(wc, wctype(“print”))	isprint(wc)
“punct”	iswctype(wc, wctype(“punct”))	ispunct(wc)
“space”	iswctype(wc, wctype(“space”))	isspace(wc)
“upper”	iswctype(wc, wctype(“upper”))	isupper(wc)
“xdigit”	iswctype(wc, wctype(“xdigit”))	isxdigit(wc)

If the wide character argument has the property indicated, iswctype() returns a nonzero value (that is, true); if not, the function returns 0 (false). Thus the call iswctype(wc, wctype("upper")) is equivalent to iswupper(wc).

The result of an iswctype() function ...