_mbctolower, _mbctolower_l, _mbctoupper, _mbctoupper_l

Tests and converts the case of a multibyte character.


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.


unsigned int _mbctolower(
   unsigned int c
unsigned int _mbctolower_l(
   unsigned int c,
   _locale_t locale
unsigned int _mbctoupper(
   unsigned int c
unsigned int _mbctoupper_l(
   unsigned int c,
   _locale_t locale


Multibyte character to convert.

Locale to use.

Return Value

Each of these functions returns the converted character c, if possible. Otherwise it returns the character c unchanged.


The functions test a character c and, if possible, apply one of the following conversions.

Routines Converts
_mbctolower, _mbctolower_l Uppercase character to lowercase character.
_mbctoupper, _mbctoupper_l Lowercase character to uppercase character.

The output value is affected by the setting of the LC_CTYPE category setting of the locale; see setlocale for more information. The version of this function without the _l suffix uses the current locale for this locale-dependent behavior; the version with the _l suffix is identical except that it uses the locale parameter passed in instead. For more information, see Locale.

In previous versions, _mbctolower was called jtolower, and _mbctoupper was called jtoupper. For new code, use the new names instead.

Generic-Text Routine Mappings

Tchar.h routine _UNICODE and _MBCS not defined _MBCS defined _UNICODE defined
_totlower tolower _mbctolower towlower
_totlower_l _tolower_l _mbctolower_l _towlower_t
_totupper toupper _mbctoupper towupper
_totupper_l toupper_l _mbctoupper_l _towupper_l


Routines Required header
_mbctolower, _mbctolower_l <mbstring.h>
_mbctoupper, _mbctoupper_l <mbstring.h>

For more compatibility information, see Compatibility.

See also

Data Conversion
_mbbtombc, _mbbtombc_l
_mbcjistojms, _mbcjistojms_l, _mbcjmstojis, _mbcjmstojis_l
_mbctohira, _mbctohira_l, _mbctokata, _mbctokata_l
_mbctombb, _mbctombb_l