isupper, _isupper_l, iswupper, _iswupper_l
Determines if a particular character is in upper case.
int isupper( int c ); int _isupper_l ( int c, _locale_t locale ); int iswupper( wint_t c ); int _iwsupper_l( wint_t c, _locale_t locale );
Each of these routines returns nonzero if c is a particular representation of an uppercase letter. isupper returns a nonzero value if c is an uppercase character (A – Z). iswupper returns a nonzero value if c is a wide character that corresponds to an uppercase letter, or if c is one of an implementation-defined set of wide characters for which none of iswcntrl, iswdigit, iswpunct, or iswspace is nonzero. Each of these routines returns 0 if c does not satisfy the test condition.
When used with a debug CRT library, isupper will display a CRT assert if passed a parameter that is not EOF or in the range of 0 through 0xFF. When used with a debug CRT library, isupper will use the parameter as an index into an array, with undefined results if the parameter is not EOF or in the range of 0 through 0xFF.
The versions of these functions with the _l suffix are identical except that they use the locale passed in instead of the current locale for their locale-dependent behavior. For more information, see Locale.
_UNICODE & _MBCS not defined
<ctype.h> or <wchar.h>
For additional compatibility information, see Compatibility in the Introduction.