Lambda va funksional interfeyslar

import java.util.*;

public class Eski {
    public static void main(String[] args) {
        List<String> shaharlar = new ArrayList<>(
                List.of("Samarqand", "Chust", "Namangan"));

        shaharlar.sort(new Comparator<String>() {
            @Override
            public int compare(String a, String b) {
                return Integer.compare(a.length(), b.length());
            }
        });

        System.out.println(shaharlar);
    }
}

import java.util.*;

public class Yangi {
    public static void main(String[] args) {
        List<String> shaharlar = new ArrayList<>(
                List.of("Samarqand", "Chust", "Namangan"));

        shaharlar.sort((a, b) -> Integer.compare(a.length(), b.length()));
        System.out.println("Uzunlik bo'yicha: " + shaharlar);

        shaharlar.sort(Comparator.comparing(String::length).reversed());
        System.out.println("Teskari:          " + shaharlar);

        shaharlar.sort(Comparator.naturalOrder());
        System.out.println("Alifbo bo'yicha:  " + shaharlar);
    }
}

public class Funksional {
    public static void main(String[] args) {
        Hisoblovchi qoshish = (a, b) -> a + b;
        Hisoblovchi kopaytirish = (a, b) -> a * b;
        Hisoblovchi kattasi = (a, b) -> a > b ? a : b;

        System.out.println("Qo'shish:     " + hisobla(7, 5, qoshish));
        System.out.println("Ko'paytirish: " + hisobla(7, 5, kopaytirish));
        System.out.println("Kattasi:      " + hisobla(7, 5, kattasi));
    }

    static int hisobla(int a, int b, Hisoblovchi amal) {
        return amal.bajar(a, b);
    }
}

@FunctionalInterface
interface Hisoblovchi {
    int bajar(int a, int b);
}

import java.util.function.*;

public class Tayyor {
    public static void main(String[] args) {
        Function<Integer, Integer> kvadrat = son -> son * son;
        Predicate<String> uzunmi = matn -> matn.length() > 5;
        Consumer<String> yozuvchi =
                matn -> System.out.println("[LOG] " + matn);
        Supplier<String> manba = () -> "yangi qiymat";
        BiFunction<Integer, Integer, Integer> qoshish = (a, b) -> a + b;
        UnaryOperator<String> katta = String::toUpperCase;

        System.out.println("Function:  " + kvadrat.apply(7));
        System.out.println("Predicate: " + uzunmi.test("Namangan"));
        yozuvchi.accept("xabar");
        System.out.println("Supplier:  " + manba.get());
        System.out.println("BiFunction:" + qoshish.apply(3, 4));
        System.out.println("Unary:     " + katta.apply("salom"));
    }
}

import java.util.function.*;

public class Shakllar {
    public static void main(String[] args) {
        Function<Integer, Integer> a = son -> son * 2;
        Function<Integer, Integer> b = (son) -> son * 2;
        Function<Integer, Integer> c = (Integer son) -> son * 2;
        Function<Integer, Integer> d = son -> {
            int natija = son * 2;
            return natija;
        };

        Supplier<String> parametrsiz = () -> "hech narsa olmaydi";
        BiFunction<Integer, Integer, Integer> ikkita = (x, y) -> x + y;

        System.out.println(a.apply(5) + ", " + b.apply(5)
                + ", " + c.apply(5) + ", " + d.apply(5));
        System.out.println(parametrsiz.get());
        System.out.println(ikkita.apply(3, 4));
    }
}

import java.util.*;
import java.util.function.*;

public class Havolalar {
    public static void main(String[] args) {
        List<String> shaharlar = new ArrayList<>(
                List.of("namangan", "andijon", "samarqand"));

        shaharlar.forEach(System.out::println);

        Function<String, Integer> uzunlik = String::length;
        System.out.println("Uzunlik: " + uzunlik.apply("Namangan"));

        Supplier<ArrayList<String>> yaratuvchi = ArrayList::new;
        System.out.println("Yangi ro'yxat: " + yaratuvchi.get());

        Function<String, String> katta = String::toUpperCase;
        System.out.println("Katta: " + katta.apply("salom"));

        BiFunction<String, String, Boolean> boshlanadimi = String::startsWith;
        System.out.println("Boshlanadimi: "
                + boshlanadimi.apply("Namangan", "Nam"));
    }
}

import java.util.function.Supplier;

public class Yopilma {
    public static void main(String[] args) {
        String salom = "Assalomu alaykum";
        Supplier<String> xabar = () -> salom + ", dunyo!";

        System.out.println(xabar.get());
        System.out.println("Ikkinchi marta: " + xabar.get());
    }
}

import java.util.function.*;

public class Birlashtirish {
    public static void main(String[] args) {
        Function<Integer, Integer> ikkiBarobar = son -> son * 2;
        Function<Integer, Integer> birQoshish = son -> son + 1;

        System.out.println("andThen: "
                + ikkiBarobar.andThen(birQoshish).apply(5));
        System.out.println("compose: "
                + ikkiBarobar.compose(birQoshish).apply(5));

        Predicate<String> uzun = m -> m.length() > 5;
        Predicate<String> nBilan = m -> m.startsWith("N");

        System.out.println("and: " + uzun.and(nBilan).test("Namangan"));
        System.out.println("or:  " + uzun.or(nBilan).test("Nur"));
        System.out.println("negate: " + uzun.negate().test("Nur"));
    }
}