isupper, _isupper_l, iswupper, _iswupper_l
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Determines whether an integer represents an uppercase character.
Syntax
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.
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 |
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.