Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All
and
div
eof
not
or
xor
Expand Minimize

tolower, _tolower, towlower, _tolower_l, _towlower_l

Converts a character to lowercase.

int tolower(
   int c 
);
int _tolower(
   int c 
);
int towlower(
   wint_t c 
);
int _tolower_l(
   int c,
   _locale_t locale 
);
int _towlower_l(
   wint_t c,
   _locale_t locale 
);

[in] c

Character to convert.

[in] locale

Locale to use for locale-specific translation.

Each of these routines converts a copy of c to lower case if the conversion is possible, and returns the result. There is no return value reserved to indicate an error.

Each of these routines converts a given uppercase letter to a lowercase letter if it is possible and relevant. The case conversion of towlower is locale-specific. Only the characters relevant to the current locale are changed in case. The functions without the _l suffix use the currently set locale. The versions of these functions that have the _l suffix take the locale as a parameter and use that instead of the currently set locale. For more information, see Locale.

In order for _tolower to give the expected results, __isascii and isupper must both return nonzero.

Generic-Text Routine Mappings

TCHAR.H routine

_UNICODE & _MBCS not defined

_MBCS defined

_UNICODE defined

_totlower

tolower

_mbctolower

towlower

_totlower_l

_tolower_l

_mbctolower_l

_towlower_l

Note Note

_tolower_l and _towlower_l have no locale dependence and are not meant to be called directly. They are provided for internal use by _totlower_l.

Routine

Required header

tolower

<ctype.h>

_tolower

<ctype.h>

towlower

<ctype.h> or <wchar.h>

For additional compatibility information, see Compatibility in the Introduction.

See the example in to Functions.

Show:
© 2015 Microsoft