toupper, _toupper, towupper, _toupper_l, _towupper_l

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06/05/2017

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The latest version of this topic can be found at toupper, _toupper, towupper, _toupper_l, _towupper_l.

Convert character to uppercase.

Syntax

int toupper(  
   int c   
);  
int _toupper(  
   int c   
);  
int towupper(  
   wint_t c   
);  
int _toupper_l(  
   int c ,  
   _locale_t locale  
);  
int _towupper_l(  
   wint_t c ,  
   _locale_t locale  
);

Parameters

c
Character to convert.

locale
Locale to use.

Return Value

Each of these routines converts a copy of c, if possible, and returns the result.

If c is a wide character for which iswlower is nonzero and there is a corresponding wide character for which iswupper is nonzero, towupper returns the corresponding wide character; otherwise, towupper returns c unchanged.

There is no return value reserved to indicate an error.

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

Remarks

Each of these routines converts a given lowercase letter to an uppercase letter if possible and appropriate. The case conversion of towupper 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 with 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 toupper to give the expected results, __isascii and isupper must both return nonzero.

Data Conversion Routines

Generic-Text Routine Mappings

TCHAR.H routine	_UNICODE & _MBCS not defined	_MBCS defined	_UNICODE defined
`_totupper`	`toupper`	`_mbctoupper`	`towupper`
`_totupper_l`	`_toupper_l`	`_mbctoupper_l`	`_towupper_l`

Note

_toupper_l and _towupper_l have no locale dependence and are not meant to be called directly. They are provided for internal use by _totupper_l.

Requirements

Routine	Required header
`toupper`	<ctype.h>
`_toupper`	<ctype.h>
`towupper`	<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::ToUpper

共用方式為