Determines if a particular character 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
);
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 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 isspacefunction depends on the LC_CTYPE category setting of the locale; see setlocale for more information. The versions of these functions without the _lsuffix use the current locale for any locale-dependent behavior; the versions with the _l suffix are identical except that they use the locale 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.
When used with a debug CRT library, isspace 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 non-debug CRT library, isspace 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.
Generic-Text Routine Mappings
| TCHAR.H routine | _UNICODE & _MBCS not defined | _MBCS defined | _UNICODE defined | 
|---|---|---|---|
| _istspace | isspace | iswspace | 
Requirements
| Routine | Required header | 
|---|---|
| isspace | <ctype.h> | 
| iswspace | <ctype.h> or <wchar.h> | 
| _isspace_l | <ctype.h> | 
| _iswspace_l | <ctype.h> or <wchar.h> | 
For additional compatibility information, see Compatibility in the Introduction.