In C++, strcoll() compares two C-strings using the sorting rules of the current language, called the locale. Unlike strcmp(), it does not use raw character codes, so accents and alphabet order can follow that language.
Both strings are required. The result is 0 when they are equal under those rules, less than 0 when the first comes first, and greater than 0 when it comes after. Call setlocale first if you need a specific language. Include <cstring>.
Compare the two strings after the locale is set.
strcoll("apple", "banana");| Call | What it does |
|---|---|
strcoll("apple", "banana") | Compares the words with the current language rules. apple comes first, so the result is less than 0. |
Set the locale with setlocale before you rely on language order. Include <clocale> for that call.
int strcoll(const char* lhs, const char* rhs);| Parameter | Description |
|---|---|
| first | Required. The first C-string. |
| second | Required. The second C-string. |
| Return Value | Description |
|---|---|
| 0 | The strings are equal under the current language rules. |
| Less than 0 | The first string comes before the second. |
| Greater than 0 | The first string comes after the second. |
Identical ASCII text compares equal, just like strcmp.
#include <iostream>
#include <cstring>
int main() {
const char* a = "CodeToFun";
const char* b = "CodeToFun";
if (strcoll(a, b) == 0) {
std::cout << "Equal\n";
}
return 0;
}strcoll(a, b) == 0 means equal under current rules.strcmp.Ask the environment for the user’s collation locale.
#include <iostream>
#include <cstring>
#include <clocale>
int main() {
setlocale(LC_COLLATE, "");
const char* left = "Apple";
const char* right = "Banana";
int result = strcoll(left, right);
if (result < 0) {
std::cout << left << " before " << right << '\n';
} else if (result > 0) {
std::cout << left << " after " << right << '\n';
} else {
std::cout << "equal\n";
}
return 0;
}setlocale(LC_COLLATE, "") selects the environment locale.strcoll then uses that language’s sort rules.strcoll vs strcmpSame call shape; different rules when the locale is set.
#include <iostream>
#include <cstring>
#include <clocale>
int main() {
setlocale(LC_COLLATE, "");
const char* a = "resume";
const char* b = "Resume";
std::cout << "strcmp: " << strcmp(a, b) << '\n';
std::cout << "strcoll: " << strcoll(a, b) << '\n';
return 0;
}strcmp compares code units—case always differs here.strcoll may treat case differently depending on locale.== 0).Copy one C-string into a destination buffer.
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