iswalpha - test for an alphabetic wide-character code
int iswalpha(wint_t wc);
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.
The iswalpha() function shall test whether wc is a wide-character code representing a character of class alpha in the program's current locale; see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale.
The wc argument is a wint_t, the value of which the application shall ensure is a wide-character code corresponding to a valid character in the current locale, or equal to the value of the macro WEOF. If the argument has any other value, the behavior is undefined.
The iswalpha() function shall return non-zero if wc is an alphabetic wide-character code; otherwise, it shall return 0.
No errors are defined.
To ensure applications portability, especially across natural languages, only this function and those listed in the SEE ALSO section should be used for classification of wide-character codes.
iswalnum(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), setlocale(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale, <stdio.h>, <wchar.h>, <wctype.h>
First released in Issue 4.
The following change has been made in this issue for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E):
The SYNOPSIS has been changed to indicate that this function and associated data types are now made visible by inclusion of the <wctype.h> header rather than <wchar.h>.
The DESCRIPTION is updated to avoid use of the term "must" for application requirements.