Satrlar

#include <print>
#include <string>
#include <string_view>
#include <vector>
#include <algorithm>
#include <sstream>

int main()
{
    std::string bosh;
    std::string salom{"Salom"};
    std::string takror(5, 'x');
    std::string nusxa{salom};
    std::string qism{salom, 0, 3};      // 0-indeksdan 3 belgi

    std::println("bosh:    '{}' ({} belgi)", bosh, bosh.size());
    std::println("salom:   '{}' ({} belgi)", salom, salom.size());
    std::println("takror:  '{}'", takror);
    std::println("nusxa:   '{}'", nusxa);
    std::println("qism:    '{}'", qism);

    // Uzunlik O(1) - saqlanadi, hisoblanmaydi
    std::println("");
    std::println("bo'shmi:      {}", bosh.empty());
    std::println("birinchi:     {}", salom.front());
    std::println("oxirgi:       {}", salom.back());

    return 0;
}

int main()
{
    std::string matn{"Salom"};

    matn += ", ";
    matn += "dunyo";
    matn.push_back('!');

    std::println("qo'shgandan keyin: {}", matn);

    matn.insert(0, ">> ");
    std::println("boshiga qo'shildi: {}", matn);

    matn.replace(3, 5, "Assalom");
    std::println("almashtirildi:     {}", matn);

    matn.erase(0, 3);
    std::println("boshi o'chirildi:  {}", matn);

    std::println("");
    std::println("katta harflarda:");
    std::string katta = matn;
    std::ranges::transform(katta, katta.begin(),
                           [](unsigned char c) { return std::toupper(c); });
    std::println("  {}", katta);

    return 0;
}

int main()
{
    std::string matn{"Husanboy Qodirov, Namangan shahri"};

    auto orin = matn.find("Qodirov");
    std::println("'Qodirov' o'rni: {}", orin);

    auto yoq = matn.find("Toshkent");
    std::println("'Toshkent' topildimi: {}",
                 yoq == std::string::npos ? "yo'q" : "ha");

    std::println("");
    std::println("boshlanadi 'Husanboy' bilan: {}",
                 matn.starts_with("Husanboy"));     // C++20
    std::println("tugaydi 'shahri' bilan:      {}",
                 matn.ends_with("shahri"));
    std::println("'Namangan' bormi:            {}",
                 matn.contains("Namangan"));        // C++23

    // Barcha vergullarni topish
    std::println("");
    std::size_t joy = 0;
    int soni = 0;
    while ((joy = matn.find(',', joy)) != std::string::npos) {
        ++soni;
        ++joy;
    }
    std::println("vergullar soni: {}", soni);

    return 0;
}

// Nusxa oladi
std::size_t nusxaBilan(std::string matn)
{
    return matn.size();
}

// Nusxa olmaydi, lekin faqat std::string qabul qiladi
std::size_t havolaBilan(const std::string& matn)
{
    return matn.size();
}

// Nusxa olmaydi va HAMMA narsani qabul qiladi
std::size_t korinishBilan(std::string_view matn)
{
    return matn.size();
}

int main()
{
    std::string s{"Husanboy Qodirov"};
    const char* c = "C uslubidagi satr";

    std::println("std::string bilan:");
    std::println("  nusxaBilan:      {}", nusxaBilan(s));
    std::println("  havolaBilan:     {}", havolaBilan(s));
    std::println("  korinishBilan:   {}", korinishBilan(s));

    std::println("");
    std::println("const char* bilan:");
    std::println("  nusxaBilan:      {}  <- vaqtinchalik string yasaldi",
                 nusxaBilan(c));
    std::println("  havolaBilan:     {}  <- vaqtinchalik string yasaldi",
                 havolaBilan(c));
    std::println("  korinishBilan:   {}  <- nusxa YO'Q", korinishBilan(c));

    std::println("");
    std::println("string_view hajmi: {} bayt", sizeof(std::string_view));
    std::println("string hajmi:      {} bayt", sizeof(std::string));

    return 0;
}

std::string_view xatoFunksiya()
{
    std::string mahalliy{"men yo'q bo'laman"};
    return mahalliy;          // string_view osilib qoladi
}

int main()
{
    // TO'G'RI ishlatish - asl obyekt hayot davomida mavjud
    std::string manba{"Husanboy Qodirov, Namangan"};
    std::string_view toliq{manba};
    std::string_view ism = toliq.substr(0, 8);
    std::string_view familiya = toliq.substr(9, 7);

    std::println("to'liq:   {}", toliq);
    std::println("ism:      {}", ism);
    std::println("familiya: {}", familiya);
    std::println("");
    std::println("uchalasi BIR XIL xotiraga ishora qiladi -");
    std::println("hech qanday nusxa olinmadi.");

    std::println("");
    std::println("xatoFunksiya() osilgan ko'rinish qaytaradi -");
    std::println("uni ishlatish aniqlanmagan xulq-atvor.");

    return 0;
}

std::vector<std::string> ajrat(std::string_view matn, char belgi)
{
    std::vector<std::string> natija;
    std::size_t boshi = 0;

    while (true) {
        std::size_t orin = matn.find(belgi, boshi);

        if (orin == std::string_view::npos) {
            natija.emplace_back(matn.substr(boshi));
            break;
        }

        natija.emplace_back(matn.substr(boshi, orin - boshi));
        boshi = orin + 1;
    }

    return natija;
}

int main()
{
    auto qismlar = ajrat("Husanboy,Malika,Nodira,Aziza", ',');

    std::println("{} ta qism:", qismlar.size());
    for (const auto& q : qismlar) {
        std::println("  '{}'", q);
    }

    // Bo'shliq bo'yicha
    auto sozlar = ajrat("bir ikki uch tort", ' ');
    std::println("");
    std::println("so'zlar: {}", sozlar);

    return 0;
}

#include <charconv>

int main()
{
    // Songa aylantirish - eski usul
    std::string matn{"12345"};
    int son = std::stoi(matn);
    double kasr = std::stod("3.14159");

    std::println("stoi:  {}", son);
    std::println("stod:  {}", kasr);

    // Satrga aylantirish
    std::println("to_string:  {}", std::to_string(42));
    std::println("format:     {}", std::format("{:.3f}", 3.14159));
    std::println("format:     {}", std::format("{:>10}", "o'ngga"));
    std::println("format:     {}", std::format("{:08.2f}", 3.14159));
    std::println("format:     {}", std::format("{:#x}", 255));

    // Xato holatlari
    std::println("");
    try {
        std::stoi("bu son emas");
    } catch (const std::invalid_argument& x) {
        std::println("stoi xatosi: {}", x.what());
    }

    // Zamonaviy usul - istisnosiz
    std::string_view kiritma{"789xyz"};
    int natija{};
    auto [oxiri, xato] = std::from_chars(kiritma.data(),
                                         kiritma.data() + kiritma.size(),
                                         natija);

    std::println("");
    std::println("from_chars: {} (qolgan qism: '{}')",
                 natija, std::string_view{oxiri});

    return 0;
}

int main()
{
    std::string a{"olma"};
    std::string b{"anor"};

    std::println("a == b:  {}", a == b);
    std::println("a < b:   {}", a < b);
    std::println("a > b:   {}", a > b);

    // C++20 - uch tomonlama solishtirish
    auto natija = a <=> b;
    std::println("");
    std::println("a <=> b: {}",
                 natija < 0 ? "kichik" : (natija > 0 ? "katta" : "teng"));

    // Tartiblash lug'at tartibida
    std::vector<std::string> mevalar{"uzum", "olma", "anor", "behi"};
    std::ranges::sort(mevalar);
    std::println("");
    std::println("tartiblangan: {}", mevalar);

    // Registrga sezgir emas solishtirish
    auto tengmi = [](std::string_view x, std::string_view y) {
        return std::ranges::equal(x, y, [](unsigned char c1, unsigned char c2) {
            return std::tolower(c1) == std::tolower(c2);
        });
    };

    std::println("");
    std::println("'Olma' va 'olma' teng: {}", tengmi("Olma", "olma"));

    return 0;
}

int main()
{
    std::println("std::string hajmi: {} bayt", sizeof(std::string));
    std::println("");

    std::string qisqa{"salom"};
    std::string uzun{"bu satr kichik satr optimallashtirishiga sig'maydi"};

    std::println("qisqa: {} belgi, sig'im {}", qisqa.size(), qisqa.capacity());
    std::println("uzun:  {} belgi, sig'im {}", uzun.size(), uzun.capacity());

    std::println("");
    std::println("Qisqa satrlar obyektning O'ZIDA saqlanadi -");
    std::println("dinamik xotira ajratilmaydi.");

    return 0;
}