Syntax

#include <wchar.h>
int wcscoll(const wchar_t *wcstr1, const wchar_t *wcstr2);

wcscoll compares the wide-character string pointed to by wcstr1 to the wide-character string pointed to by wcstr2, both interpreted according to the information in the LC_COLLATE category of the current locale.

wcscoll differs from the wcscmp function. wcscoll performs a comparison between two wide-character strings based on language collation rules as controlled by the LC_COLLATE category. In contrast, wcscmp performs a wide-character code to wide-character code comparison. If a string will be collated many times, as when inserting an entry into a sorted list, wcsxfrm followed by wcscmp can be more efficient.

wcscoll returns an integer value indicating the relationship between the strings, as listed below: compact break=fit.

Value

Meaning
Less than 0
wcstr1 less than wcstr2
0
wcstr1 equivalent to wcstr2
Greater than 0
wcstr1 greater than wcstr2

If wcs1 or wcs2 contain characters outside the domain of the collating sequence, wcscoll sets errno to EILSEQ. If an error occurs, wcscoll sets errno to a nonzero value. There is no error return value.

This example uses wcscoll to compare two wide-character strings.

#include <wchar.h>#include <locale.h>
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
   wchar_t *wcs1 = L"A wide string";
   wchar_t *wcs2 = L"a wide string";
   int     result;

   if (NULL == setlocale(LC_ALL, "Ja_JP")) {
      printf("setlocale failed.\n");
      exit(EXIT_FAILURE);
   }
   result = wcscoll(wcs1, wcs2);
   if (0 == result)
      printf("\"%ls\" is identical to \"%ls\"\n", wcs1, wcs2);
   else if (0 > result)
      printf("\"%ls\" is less than \"%ls\"\n", wcs1, wcs2);
   else
      printf("\"%ls\" is greater than \"%ls\"\n", wcs1, wcs2);
   return 0;

   /****************************************************************************
      The output should be similar to :

      "A wide string" is identical to "a wide string"
   ****************************************************************************/
}

• strcoll
  
• setlocale
  
• wcscmp
  
• wcsxfrm

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