isspace, iswspace, _isspace_l, _iswspace_l

Determines whether an integer represents a space character.


int isspace(
   int c
int iswspace(
   wint_t c
int _isspace_l(
   int c,
   _locale_t locale
int _iswspace_l(
   wint_t c,
   _locale_t locale


Integer to test.

Locale to use.

Return value

Each of these routines returns nonzero if c is a particular representation of a space character. isspace returns a nonzero value if c is a white-space character (0x09 - 0x0D or 0x20). The result of the test condition for the isspace function depends on the LC_CTYPE category setting of the locale. For more information, see setlocale, _wsetlocale. The versions of these functions that don't have the _l suffix use the current locale for any locale-dependent behavior; the versions that do have the _l suffix are identical except that they use the locale that's passed in instead. For more information, see Locale.

iswspace returns a nonzero value if c is a wide character that corresponds to a standard white-space character.

The behavior of isspace and _isspace_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

TCHAR.H routine _UNICODE and _MBCS not defined _MBCS defined _UNICODE defined
_istspace isspace _ismbcspace iswspace


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


Routine Required header
isspace <ctype.h>
iswspace <ctype.h> or <wchar.h>
_isspace_l <ctype.h>
_iswspace_l <ctype.h> or <wchar.h>

For more compatibility information, see Compatibility.

See also

Character classification
is, isw routines