_stricoll, _wcsicoll, _mbsicoll, _stricoll_l, _wcsicoll_l, _mbsicoll_l

Compares strings by using locale-specific information.


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


int _stricoll(
   const char *string1,
   const char *string2
int _wcsicoll(
   const wchar_t *string1,
   const wchar_t *string2
int _mbsicoll(
   const unsigned char *string1,
   const unsigned char *string2
int _stricoll_l(
   const char *string1,
   const char *string2,
   _locale_t locale
int _wcsicoll_l(
   const wchar_t *string1,
   const wchar_t *string2,
   _locale_t locale
int _mbsicoll_l(
   const unsigned char *string1,
   const unsigned char *string2,
   _locale_t locale


string1, string2
Null-terminated strings to compare.

The locale to use.

Return Value

Each of these functions returns a value indicating the relationship of string1 to string2, as follows.

Return value Relationship of string1 to string2
< 0 string1 less than string2
0 string1 identical to string2
> 0 string1 greater than string2
_NLSCMPERROR An error occurred.

Each of these functions returns _NLSCMPERROR. To use _NLSCMPERROR, include either <string.h> or <mbstring.h>. _wcsicoll can fail if either string1 or string2 contains wide-character codes outside the domain of the collating sequence. When an error occurs, _wcsicoll may set errno to EINVAL. To check for an error on a call to _wcsicoll, set errno to 0 and then check errno after calling _wcsicoll.


Each of these functions performs a case-insensitive comparison of string1 and string2 according to the code page currently in use. These functions should be used only when there is a difference between the character set order and the lexicographic character order in the current code page and this difference is of interest for the string comparison.

_stricmp differs from _stricoll in that the _stricmp comparison is affected by LC_CTYPE, whereas the _stricoll comparison is according to the LC_CTYPE and LC_COLLATE categories of the locale. For more information on the LC_COLLATE category, see setlocale and Locale Categories. The versions of these functions without the _l suffix use the current locale; the versions with the _l suffix are identical except that they use the locale passed in instead. For more information, see Locale.

All of these functions validate their parameters. If either string1 or string2 are NULL pointers, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, these functions return _NLSCMPERROR and set errno to EINVAL.

Generic-Text Routine Mappings

TCHAR.H routine _UNICODE & _MBCS not defined _MBCS defined _UNICODE defined
_tcsicoll _stricoll _mbsicoll _wcsicoll


Routine Required header
_stricoll, _stricoll_l <string.h>
_wcsicoll, _wcsicoll_l <wchar.h>, <string.h>
_mbsicoll, _mbsicoll_l <mbstring.h>

For additional compatibility information, see Compatibility.

See also

String Manipulation
strcoll Functions
_mbsnbcoll, _mbsnbcoll_l, _mbsnbicoll, _mbsnbicoll_l
setlocale, _wsetlocale
strcmp, wcscmp, _mbscmp
_stricmp, _wcsicmp, _mbsicmp, _stricmp_l, _wcsicmp_l, _mbsicmp_l
strncmp, wcsncmp, _mbsncmp, _mbsncmp_l
_strnicmp, _wcsnicmp, _mbsnicmp, _strnicmp_l, _wcsnicmp_l, _mbsnicmp_l
strxfrm, wcsxfrm, _strxfrm_l, _wcsxfrm_l