isleadbyte-isleadbyte-l.md

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Learn more about: isleadbyte, _isleadbyte_l	isleadbyte, _isleadbyte_l	4/2/2020	_isleadbyte_l isleadbyte _o__isleadbyte_l _o_isleadbyte	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-string-l1-1-0.dll	DLLExport	apiref	_istleadbyte _isleadbyte_l isleadbyte	lead bytes _isleadbyte_l function _istleadbyte function istleadbyte function isleadbyte function	3b2bcf09-d82b-4803-9e80-59d04942802a

isleadbyte, _isleadbyte_l

Determines whether a character is the lead byte of a multibyte character.

Important

This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported in Universal Windows Platform apps.

Syntax

int isleadbyte( int c );
int _isleadbyte_l( int c );

Parameters

c
Integer to test.

Return value

isleadbyte returns a nonzero value if the argument satisfies the test condition. Otherwise, it returns 0. In the "C" locale and in single-byte character set (SBCS) locales, isleadbyte always returns 0.

Remarks

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 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.

The version of this function with the _l suffix is identical except that it uses the locale passed in instead of the current locale for its locale-dependent behavior.

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

Generic-text routine mappings

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

Requirements

Routine	Required header
isleadbyte	<ctype.h>
_isleadbyte_l	<ctype.h>

For more compatibility information, see Compatibility.

See also

Byte classification
Locale
_ismbb routines