std:: strcoll

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

Parameters

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 .

Notes

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" .

Example

#include <clocale>
#include <cstring>
#include <iostream>
 
int main()
{
    std::setlocale(LC_COLLATE, "cs_CZ.utf8");
    // Alternatively, ISO-8859-2 (a.k.a. Latin-2)
    // may also work on some OS:
    // std::setlocale(LC_COLLATE, "cs_CZ.iso88592");
 
    const char* s1 = "hrnec";
    const char* s2 = "chrt";
 
    std::cout << "In the Czech locale: ";
    if (std::strcoll(s1, s2) < 0)
        std::cout << s1 << " before " << s2 << '\n';
    else
        std::cout << s2 << " before " << s1 << '\n';
 
    std::cout << "In lexicographical comparison: ";
    if (std::strcmp(s1, s2) < 0)
        std::cout << s1 << " before " << s2 << '\n';
    else
        std::cout << s2 << " before " << s1 << '\n';
}

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

See also