islower, iswlower, _islower_l, _iswlower_l
Determines if a particular character is in lower case.
int islower(
int c
);
int iswlower(
wint_t c
);
int islower_l(
int c,
_locale_t locale
);
int _iswlower_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 a lowercase character. islower returns a nonzero value if c is a lowercase character (a – z). iswlower returns a nonzero value if c is a wide character that corresponds to a lowercase 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 release CRT library, islower 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, islower 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 |
|---|---|---|---|
_istlower |
islower |
iswlower |
|
_istlower_l |
_islower _l |
_liswlower_l |
Requirements
Routine |
Required header |
|---|---|
islower |
<ctype.h> |
iswlower |
<ctype.h> or <wchar.h> |
_islower_l |
<ctype.h> |
_swlower_l |
<ctype.h> or <wchar.h> |
For additional compatibility information, see Compatibility in the Introduction.