isupper, _isupper_l, iswupper, _iswupper_l
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at isupper, _isupper_l, iswupper, _iswupper_l.
Determines whether an integer represents an uppercase character.
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.
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.
The versions of these functions that have the _l suffix use the locale that's passed in instead of the current locale for their locale-dependent behavior. For more information, see Locale.
The behavior of isupper and _isupper_l is undefined if c is not EOF or in the range 0 through 0xFF, inclusive. When a debug CRT library is used and c is not one of these values, the functions raise an assertion.
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 |
| 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.