tolower, _tolower, towlower, _tolower_l, _towlower_l

Article
06/05/2017

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The latest version of this topic can be found at tolower, _tolower, towlower, _tolower_l, _towlower_l.

Converts a character to lowercase.

Syntax

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   
);

Parameters

[in] c
Character to convert.

[in] locale
Locale to use for locale-specific translation.

Return Value

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.

Remarks

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

_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.

Requirements

Routine	Required header
`tolower`	<ctype.h>
`_tolower`	<ctype.h>
`towlower`	<ctype.h> or <wchar.h>

For additional compatibility information, see Compatibility in the Introduction.

Example

See the example in to Functions.

.NET Framework Equivalent

System::Char::ToLower

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