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 
);

Parameters

• c
  Integer to test.

• locale
  Locale to use.

Return Value

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.

Generic-Text Routine Mappings

TCHAR.H routine	_UNICODE & _MBCS not defined	_MBCS defined	_UNICODE defined
_istupper	isupper	_ismbcupper	iswupper
_istupper_l	_isupper_l	_ismbclower, _ismbclower_l, _ismbcupper, _ismbcupper_l	_iswupper_l

Requirements

Routine	Required header
isupper	<ctype.h>
_isupper_l	<ctype.h>
iswupper	<ctype.h> or <wchar.h>
_iswupper_l	<ctype.h>

For additional compatibility information, see Compatibility in the Introduction.

.NET Framework Equivalent

System::Char::IsUpper

See Also

Concepts

Character Classification

Locale

is, isw Routines