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 doesn't 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__ isn't defined or is defined as 0; otherwise it's undefined.

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

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 more compatibility information, see Compatibility.

See also

Character classification
Locale
is, isw routines