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int isleadbyte(
   int c 


Integer to test.

Return Value

isleadbyte returns a nonzero value if the argument satisfies the test condition or 0 if it does not. In the "C" locale and in single-byte character set (SBCS) locales, isleadbyte always returns 0.


The isleadbyte macro returns a nonzero value if its argument is the first byte of a multibyte character. isleadbyte produces a meaningful result for any integer argument from –1 (EOF) to UCHAR_MAX (0xFF), inclusive. The result of the test depends upon the LC_CTYPE category setting of the current locale; see setlocale for more information.

The expected argument type of isleadbyte is int; if a signed character is passed, the compiler may convert it to an integer by sign extension, yielding unpredictable results.

Generic-Text Routine Mappings

TCHAR.H routine _UNICODE & _MBCS not defined _MBCS defined _UNICODE defined
_istleadbyte Always returns false _isleadbyte Always returns false


Routine Required header Compatibility
isleadbyte <ctype.h> ANSI, Win 98, Win Me, Win NT, Win 2000, Win XP

For additional compatibility information, see Compatibility in the Introduction.


All versions of the C run-time libraries.

See Also

Byte Classification Routines | Locale Routines | _ismbb Routines | Run-Time Routines and .NET Framework Equivalents