isascii, __isascii, iswascii
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at isascii, __isascii, iswascii.
Determines whether a particular character is an ASCII character.
int __isascii( int c ); int iswascii( wint_t c ); #define isascii __isascii
Parameters
c
Integer to test.
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.
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 |
| 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.