clocale

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1. Setting Locale

#include <locale>

setlocale(LC_ALL, "en_US.UTF-8");

2. Getting Current Locale

#include <locale>

char* locale = setlocale(LC_ALL, NULL);

3. Using Numeric Formatting

#include <locale>
#include <iomanip>

double value = 123.456;
std::cout << std::fixed << std::setprecision(2) << value << std::endl; // 123.46

4. Using Monetary Formatting

#include <locale>
#include <iomanip>

double amount = 1000.0;
std::cout << std::fixed << std::setprecision(2) << std::showpoint << std::setmoneyfmt(std::moneypunct<char>().curr_symbol()) << amount << std::endl; // $1,000.00

5. Using Datetime Formatting

#include <locale>
#include <ctime>
#include <iostream>

time_t now = time(nullptr);
std::cout << std::put_time(std::localtime(&now), "%c") << std::endl; // Tue Sep 13 10:43:39 2022

6. Using Collation

#include <locale>
#include <algorithm>

std::locale loc("en_US.UTF-8");
std::sort(vec.begin(), vec.end(), [](const std::string& a, const std::string& b) { return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end(), loc); });

7. Using Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::wcout.imbue(loc);

8. Using Monetary Facets

#include <locale>
#include <iomanip>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::cout << std::fixed << std::setprecision(2) << std::showpoint << std::setmoneyfmt(std::moneypunct<char>().curr_symbol()) << 1000.0 << std::endl; // $1,000.00

9. Using Datetime Facets

#include <locale>
#include <ctime>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
time_t now = time(nullptr);
std::cout << std::put_time(std::localtime(&now), "%c") << std::endl; // Tue Sep 13 10:43:39 2022

10. Using Character Classification Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::cout << std::boolalpha << std::isupper('A', loc) << std::endl; // true

11. Using String Conversion Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::wstring wide_str = L"你好";
std::string narrow_str(wide_str.begin(), wide_str.end(), loc);
std::cout << narrow_str << std::endl; // 你好

12. Using Collation Facets

#include <locale>
#include <algorithm>

std::locale loc("en_US.UTF-8");
std::collator<char> collator(loc);
std::cout << std::boolalpha << collator.compare("a", "b") < 0 << std::endl; // true

13. Using Numpunct Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::cout << std::fixed << std::setprecision(2) << 1000.0 << std::endl; // 1,000.00

14. Using Timepunct Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
time_t now = time(nullptr);
std::cout << std::put_time(std::localtime(&now), "%c") << std::endl; // Tue Sep 13 10:43:39 2022

15. Using Message Facets

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::cout << std::messages::get("hello") << std::endl; // hello

16. Using Classification

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << (std::isupper('A', loc) ? L"Upper" : L"Lower") << std::endl; // Upper

17. Using String Conversion

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wstring wide_str = L"你好";
std::string narrow_str(wide_str.begin(), wide_str.end(), loc);
std::wcout << narrow_str << std::endl; // 你好

18. Using Comparison

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << (std::wlexicographical_compare(L"a", L"b", loc) ? L"Less" : L"Greater") << std::endl; // Less

19. Using Number Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::fixed << std::setprecision(2) << 1000.0 << std::endl; // 1,000.00

20. Using Date and Time Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
time_t now = time(nullptr);
std::wcout << std::put_time(std::localtime(&now), L"%c") << std::endl; // Tue Sep 13 10:43:39 2022

21. Using Message Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::messages::get(L"hello") << std::endl; // hello

22. Using Codecvt Facet

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wstring wide_str = L"你好";
std::string narrow_str;
std::codecvt<wchar_t, char> converter;
converter.out(std::wstring_convert<wchar_t, char>::convert_type::narrow, wide_str.begin(), wide_str.end(), std::back_inserter(narrow_str));
std::cout << narrow_str << std::endl; // 你好

23. Using Character Classification

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << (std::isupper(L'A', loc) ? L"Upper" : L"Lower") << std::endl; // Upper

24. Using Wide String Conversion

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wstring wide_str = L"你好";
std::string narrow_str(wide_str.begin(), wide_str.end(), loc);
std::wcout << narrow_str << std::endl; // 你好

25. Using Wide String Comparison

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << (std::wlexicographical_compare(L"a", L"b", loc) ? L"Less" : L"Greater") << std::endl; // Less

26. Using Wide Number Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::fixed << std::setprecision(2) << 1000.0 << std::endl; // 1,000.00

27. Using Wide Date and Time Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
time_t now = time(nullptr);
std::wcout << std::put_time(std::localtime(&now), L"%c") << std::endl; // Tue Sep 13 10:43:39 2022

28. Using Wide Message Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::messages::get(L"hello") << std::endl; // hello

29. Using Generic Character Classification

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout.imbue(loc);
std::cout << (std::isupper('A', std::locale::classic()) ? "Upper" : "Lower") << std::endl; // Upper

30. Using Generic String Conversion

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wstring wide_str = L"你好";
std::string narrow_str(wide_str.begin(), wide_str.end(), std::locale::classic());
std::wcout << narrow_str << std::endl; // 你好

31. Using Generic Comparison

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << (std::wlexicographical_compare(L"a", L"b", std::locale::classic()) ? L"Less" : L"Greater") << std::endl; // Less

32. Using Generic Number Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::fixed << std::setprecision(2) << 1000.0 << std::locale::classic() << std::endl; // 1,000.00

33. Using Generic Date and Time Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
time_t now = time(nullptr);
std::wcout << std::put_time(std::localtime(&now), L"%c", std::locale::classic()) << std::endl; // Tue Sep 13 10:43:39 2022

34. Using Generic Message Formatting

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::wcout.imbue(loc);
std::wcout << std::messages::get(L"hello", std::locale::classic()) << std::endl; // hello

35. Using Global Locale

#include <locale>
#include <iostream>

std::locale::global(std::locale("en_US.UTF-8"));
std::cout << std::fixed << std::setprecision(2) << 1000.0 << std::endl; // 1,000.00

36. Using Default Locale

#include <locale>
#include <iostream>

std::cout.imbue(std::locale());
std::cout << std::fixed << std::setprecision(2) << 1000.0 << std::endl; // 1,000.00

37. Using Copy Constructor

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2(loc1);

38. Using Move Constructor

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2(std::move(loc1));

39. Using Assignment Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2;
loc2 = loc1;

40. Using Equality Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("en_US.UTF-8");
std::cout << std::boolalpha << (loc1 == loc2) << std::endl; // true

41. Using Inequality Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("fr_FR.UTF-8");
std::cout << std::boolalpha << (loc1 != loc2) << std::endl; // true

42. Using Less Than Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("fr_FR.UTF-8");
std::cout << std::boolalpha << (loc1 < loc2) << std::endl; // true

43. Using Greater Than Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("fr_FR.UTF-8");
std::cout << std::boolalpha << (loc1 > loc2) << std::endl; // false

44. Using Less Than or Equal To Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("en_US.UTF-8");
std::cout << std::boolalpha << (loc1 <= loc2) << std::endl; // true

45. Using Greater Than or Equal To Operator

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("en_US.UTF-8");
std::cout << std::boolalpha << (loc1 >= loc2) << std::endl; // true

46. Using Subscript Operator

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout << loc[std::locale::numeric_facet]() << std::endl; // decimal point separator

47. Using at Function

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout << loc.at(std::locale::numeric_facet)() << std::endl; // decimal point separator

48. Using has_facet Function

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout << std::boolalpha << loc.has_facet<std::moneypunct<char>>() << std::endl; // true

49. Using facet Method

#include <locale>
#include <iostream>

std::locale loc("en_US.UTF-8");
std::cout << loc.facet<std::moneypunct<char>>().curr_symbol() << std::endl; // $

50. Using swap Method

#include <locale>
#include <iostream>

std::locale loc1("en_US.UTF-8");
std::locale loc2("fr_FR.UTF-8");
loc1.swap(loc2);