islower, iswlower, _islower_l, _iswlower_l

Determines whether an integer represents a lowercase character.

Syntax

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 doesn't 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 islower and _islower_l is undefined if c isn't EOF or in the range 0 through 0xFF, inclusive. When a debug CRT library is used and c isn't one of these values, the functions raise an assertion.

Generic-text routine mappings

Remarks

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

For more compatibility information, see Compatibility.

See also

Character classification
Locale
is, isw routines