isascii, __isascii, iswascii

Determines whether a particular character is an ASCII character.

Syntax

int __isascii(
   int c
);
int iswascii(
   wint_t c
);

#define isascii __isascii

Parameters

c
Integer to test.

Return Value

Each of these routines returns nonzero if c is a particular representation of an ASCII character. __isascii returns a nonzero value if c is an ASCII character (in the range 0x00 - 0x7F). iswascii returns a nonzero value if c is a wide-character representation of an ASCII character. Each of these routines returns 0 if c does not satisfy the test condition.

Remarks

Both __isascii and iswascii are implemented as macros unless the preprocessor macro _CTYPE_DISABLE_MACROS is defined.

For backward compatibility, isascii is implemented as a macro only if __STDC__ is not defined or is defined as 0; otherwise it is undefined.

Generic-Text Routine Mappings

Tchar.h routine _UNICODE and _MBCS not defined _MBCS defined _UNICODE defined
_istascii __isascii __isascii iswascii

Requirements

Routine Required header
isascii, __isascii C: <ctype.h>

C++: <cctype> or <ctype.h>
iswascii C: <wctype.h>, <ctype.h>, or <wchar.h>

C++: <cwctype>, <cctype>, <wctype.h>, <ctype.h>, or <wchar.h>

The isascii, __isascii and iswascii functions are Microsoft specific. For additional compatibility information, see Compatibility in the Introduction.

See Also

Character Classification
Locale
is, isw Routines