std::basic_string<CharT,Traits,Allocator>::size, std::basic_string<CharT,Traits,Allocator>::length - cppreference.com (original) (raw)

Returns the number of CharT elements in the string, i.e. std::distance(begin(), end()).

[edit] Parameters

(none)

[edit] Return value

The number of CharT elements in the string.

[edit] Complexity

[edit] Notes

For std::string, the elements are bytes (objects of type char), which are not the same as characters if a multibyte encoding such as UTF-8 is used.

[edit] Example

#include #include #include   int main() { std::string s("Exemplar"); assert(8 == s.size()); assert(s.size() == s.length()); assert(s.size() == static_caststd:🧵:size_type( std::distance(s.begin(), s.end())));   std::u32string a(U"ハロー・ワールド"); // 8 code points assert(8 == a.size()); // 8 code units in UTF-32   std::u16string b(u"ハロー・ワールド"); // 8 code points assert(8 == b.size()); // 8 code units in UTF-16   std::string c("ハロー・ワールド"); // 8 code points assert(24 == c.size()); // 24 code units in UTF-8   #if __cpp_lib_char8_t >= 201907L std::u8string d(u8"ハロー・ワールド"); // 8 code points assert(24 == d.size()); // 24 code units in UTF-8 #endif }

[edit] See also

| | checks whether the string is empty (public member function) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns the maximum number of characters (public member function) [edit] | | | returns the number of characters (public member function of std::basic_string_view<CharT,Traits>) [edit] |