Defined in header <string.h>
int strcoll( const char *lhs, const char *rhs );

Compares two null-terminated byte strings according to the current locale as defined by the LC_COLLATE category.


lhs, rhs - pointers to the null-terminated byte strings to compare

Return value

Negative value if lhs is less than (precedes) rhs.

​0​ if lhs is equal to rhs.

Positive value if lhs is greater than (follows) rhs.


Collation order is the dictionary order: the position of the letter in the national alphabet (its equivalence class) has higher priority than its case or variant. Within an equivalence class, lowercase characters collate before their uppercase equivalents and locale-specific order may apply to the characters with diacritics. In some locales, groups of characters compare as single collation units. For example, "ch" in Czech follows "h" and precedes "i", and "dzs" in Hungarian follows "dz" and precedes "g".


#include <stdio.h>
#include <string.h>
#include <locale.h>
int main(void)
    setlocale(LC_COLLATE, "cs_CZ.iso88592");
    const char* s1 = "hrnec";
    const char* s2 = "chrt";
    printf("In the Czech locale: ");
    if(strcoll(s1, s2) < 0)
         printf("%s before %s\n", s1, s2);
         printf("%s before %s\n", s2, s1);
    printf("In lexicographical comparison: ");
    if(strcmp(s1, s2) < 0)
         printf("%s before %s\n", s1, s2);
         printf("%s before %s\n", s2, s1);


In the Czech locale: hrnec before chrt
In lexicographical comparison: chrt before hrnec


  • C11 standard (ISO/IEC 9899:2011):
    • The strcoll function (p: 366)
  • C99 standard (ISO/IEC 9899:1999):
    • The strcoll function (p: 329)
  • C89/C90 standard (ISO/IEC 9899:1990):
    • The strcoll function

See also

compares two wide strings in accordance to the current locale
transform a string so that strcmp would produce the same result as strcoll
transform a wide string so that wcscmp would produce the same result as wcscoll
compares two strings
C++ documentation for strcoll

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.