std::basic_string::size,(3)

💅 std::basic_string::size,(3) 💅

okay bestie, welcome to the C++ Standard Libary page for std::basic_string::size,(3) — yes, that's the manual name, typo and all, and we're keeping every detail. this page is giving “how many CharT elements are in the string?” energy. 🎀

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🎀 NAME 🎀

the whole NAME line is literally:

std::basic_string::size, - std::basic_string::size,

slay, it says the same thing twice, and we are not fixing it. 💖

✨ Synopsis ✨

two overloads, both here for your counting needs:

size_type size() const;   (1) (noexcept since C++11)
                              (constexpr since C++20)
size_type length() const; (2) (noexcept since C++11)
                              (constexpr since C++20)

and yeah, it returns the number of CharT elements in the string, i.e. std::distance(begin(), end()). no cap. 💅

🌸 Parameters 🌸

none. zero. zilch. this one takes no parameters. 🙈

💖 Return value 💖

the number of CharT elements in the string. that's it, that's the tea. 🍓

🌟 Complexity 🌟

• Unspecified (until C++11)
• Constant (since C++11)

bestie, it got upgraded. 🔥

🦋 Notes 🦋

for std::string, the elements are bytes (objects of type char), and those are not the same as characters if a multibyte encoding such as UTF-8 is used. so like, do not confuse bytes with characters, iykyk. 😭

💻 Example 💻

the page says run this code, so here it is, exactly:

#include <cassert>
#include <iterator>
#include <string>

int main()
{
    std::string s("Exemplar");
    assert(8 == s.size());
    assert(s.size() == s.length());
    assert(s.size() == static_cast<std::string::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 __cplusplus >= 202002
    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
}

not me gasping at the 24 bytes for 8 code points in UTF-8 — the example is literally showing off the difference. 👑

🌈 See also 🌈

• empty — checks whether the string is empty (public member function)
• max_size — returns the maximum number of characters (public member function)
• size — returns the number of characters
• length — (public member function of std::basic_string_view<CharT,Traits>)

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kisses bestie, that's the whole page 💖 it's from http://cppreference.com, dated 2024.06.10, with the page label std::basic_string::size,(3). periodt. 🎀