Export (0) Print
Expand All
div
eof
Expand Minimize

isalnum, iswalnum, _isalnum_l, _iswalnum_l

Determines whether an integer represents an alphanumeric character.

int isalnum( 
   int c 
);
int iswalnum( 
   wint_t c 
);
int _isalnum_l( 
   int c,
   _locale_t locale
);
int _iswalnum_l( 
   wint_t c,
   _locale_t locale
);

c

Integer to test.

locale

The locale to use.

Each of these routines returns nonzero if c is a particular representation of an alphanumeric character. isalnum returns a nonzero value if either isalpha or isdigit is nonzero for c, that is, if c is within the ranges A – Z, a – z, or 0 – 9. iswalnum returns a nonzero value if either iswalpha or iswdigit is nonzero for c. 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 parameter that's passed in instead of the current locale. For more information, see Locale.

The behavior of isalnum and _isalnum_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

_istalnum

isalnum

_ismbcalnum

iswalnum

_istalnum_l

_isalnum_l

_ismbcalnum_l

_iswalnum_l

Routine

Required header

isalnum

<ctype.h>

iswalnum

<ctype.h> or <wchar.h>

_isalnum_l

<ctype.h>

_iswalnum_l

<ctype.h> or <wchar.h>

For additional compatibility information, see Compatibility.

Show:
© 2014 Microsoft