Kolleksiyalar

import java.util.ArrayList;
import java.util.List;

public class Royxat {
    public static void main(String[] args) {
        List<String> talabalar = new ArrayList<>();

        talabalar.add("Husanboy");
        talabalar.add("Malika");
        talabalar.add("Nodira");
        talabalar.add(0, "Kamola");
        talabalar.remove("Malika");

        System.out.println("Soni: " + talabalar.size());
        System.out.println(talabalar);
        System.out.println("Nodira bormi: " + talabalar.contains("Nodira"));
        System.out.println("Birinchi: " + talabalar.get(0));
        System.out.println("Nodira o'rni: " + talabalar.indexOf("Nodira"));
    }
}

import java.util.*;

public class Ikki {
    public static void main(String[] args) {
        List<String> a = new ArrayList<>(List.of("bir", "ikki"));
        List<String> b = new LinkedList<>(List.of("bir", "ikki"));

        a.add("uch");
        b.add(0, "nol");

        System.out.println("ArrayList:  " + a);
        System.out.println("LinkedList: " + b);
        System.out.println("Teng-mi: " + a.equals(new ArrayList<>(a)));
    }
}

import java.util.LinkedHashMap;
import java.util.Map;

public class Lugat {
    public static void main(String[] args) {
        Map<String, Integer> aholi = new LinkedHashMap<>();

        aholi.put("Namangan", 626000);
        aholi.put("Andijon", 441000);
        aholi.put("Chust", 68000);
        aholi.put("Namangan", 630000);          // eskisini almashtiradi

        System.out.println("Shaharlar soni: " + aholi.size());
        System.out.println("Namangan: " + aholi.get("Namangan"));
        System.out.println("Buxoro: " + aholi.get("Buxoro"));
        System.out.println("Buxoro (sukut): "
                + aholi.getOrDefault("Buxoro", 0));
        System.out.println("Chust bormi: " + aholi.containsKey("Chust"));

        for (Map.Entry<String, Integer> yozuv : aholi.entrySet()) {
            System.out.printf("  %-10s %8d%n",
                    yozuv.getKey(), yozuv.getValue());
        }
    }
}

import java.util.Map;
import java.util.TreeMap;

public class Saralangan {
    public static void main(String[] args) {
        Map<String, Integer> aholi = new TreeMap<>();

        aholi.put("Namangan", 626000);
        aholi.put("Andijon", 441000);
        aholi.put("Samarqand", 551000);

        System.out.println(aholi.keySet());

        TreeMap<String, Integer> daraxt = new TreeMap<>(aholi);
        System.out.println("Birinchi kalit: " + daraxt.firstKey());
        System.out.println("Oxirgi kalit:   " + daraxt.lastKey());
    }
}

import java.util.LinkedHashMap;
import java.util.Map;

public class MapMetodlar {
    public static void main(String[] args) {
        Map<String, Integer> hisob = new LinkedHashMap<>();

        String[] sozlar = {"olma", "behi", "olma", "uzum", "olma"};

        for (String soz : sozlar) {
            hisob.merge(soz, 1, Integer::sum);
        }
        System.out.println("merge bilan:  " + hisob);

        Map<String, Integer> boshqa = new LinkedHashMap<>();
        for (String soz : sozlar) {
            boshqa.put(soz, boshqa.getOrDefault(soz, 0) + 1);
        }
        System.out.println("getOrDefault: " + boshqa);

        hisob.putIfAbsent("anor", 1);
        hisob.computeIfPresent("olma", (k, v) -> v * 10);
        System.out.println("Yakuniy:      " + hisob);
    }
}

import java.util.*;

public class Toplam {
    public static void main(String[] args) {
        Set<String> a = new LinkedHashSet<>(
                List.of("Namangan", "Andijon", "Samarqand"));

        boolean qoshildi = a.add("Andijon");
        System.out.println("Qayta qo'shildimi: " + qoshildi);
        System.out.println("Soni: " + a.size());

        Set<String> b = new LinkedHashSet<>(List.of("Andijon", "Buxoro"));

        Set<String> umumiy = new LinkedHashSet<>(a);
        umumiy.retainAll(b);
        System.out.println("Umumiy: " + umumiy);

        Set<String> farq = new LinkedHashSet<>(a);
        farq.removeAll(b);
        System.out.println("Faqat a da: " + farq);
    }
}

import java.util.ArrayDeque;
import java.util.Deque;

public class Navbat {
    public static void main(String[] args) {
        Deque<String> navbat = new ArrayDeque<>();
        navbat.addLast("Husanboy");
        navbat.addLast("Malika");
        navbat.addLast("Nodira");

        System.out.println("Navbatdan: " + navbat.pollFirst());
        System.out.println("Keyingisi: " + navbat.peekFirst());

        Deque<String> taxlam = new ArrayDeque<>();
        taxlam.push("birinchi");
        taxlam.push("ikkinchi");
        taxlam.push("uchinchi");

        System.out.println("Taxlamdan: " + taxlam.pop());
    }
}

import java.util.List;
import java.util.Map;

public class Ozgarmas {
    public static void main(String[] args) {
        List<String> royxat = List.of("bir", "ikki", "uch");
        Map<String, Integer> lugat = Map.of("bir", 1, "ikki", 2);

        System.out.println(royxat);
        System.out.println("Lug'atda 'bir': " + lugat.get("bir"));

        try {
            royxat.add("to'rt");
        } catch (UnsupportedOperationException x) {
            System.out.println("Istisno: " + x.getClass().getSimpleName());
        }
    }
}