Java List’ni saralash

Java List’ni saralash

Oldingi boblarda Java tilidagi ikkita mashhur ro‘yxat — java.util paketida joylashgan ArrayList va LinkedList’dan qanday foydalanishni o‘rgandingiz.

java.util paketidagi yana bir foydali sinf — Collections sinfi; unda ro‘yxatlarni alifbo yoki son tartibida saralash uchun sort() metodi bor.

ArrayList’ni saralash

Stringlardan iborat ArrayList’ni alifbo bo‘yicha o‘sish tartibida saralang:

import java.util.ArrayList;
import java.util.Collections;  // Import the Collections class

public class Main {
  public static void main(String[] args) {
    ArrayList<String> cars = new ArrayList<String>();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("Mazda");

    Collections.sort(cars);  // Sort cars

    for (String i : cars) {
      System.out.println(i);
    }
  }
}

Butun sonlardan (Integer) iborat ArrayList’ni son qiymati bo‘yicha o‘sish tartibida saralang:

import java.util.ArrayList;
import java.util.Collections;  // Import the Collections class

public class Main {
  public static void main(String[] args) {
    ArrayList<Integer> myNumbers = new ArrayList<Integer>();
    myNumbers.add(33);
    myNumbers.add(15);
    myNumbers.add(20);
    myNumbers.add(34);
    myNumbers.add(8);
    myNumbers.add(12);

    Collections.sort(myNumbers);  // Sort myNumbers

    for (int i : myNumbers) {
      System.out.println(i);
    }
  }
}

Tartibni teskari aylantirish

reverseOrder() metodi yordamida ro‘yxatni teskari tartibda ham saralashingiz mumkin.

Quyidagi misolda stringlardan iborat ArrayList’ni alifbo bo‘yicha teskari (kamayish) tartibida saralaymiz:

import java.util.ArrayList;
import java.util.Collections;  // Import the Collections class

public class Main {
  public static void main(String[] args) {
    ArrayList<String> cars = new ArrayList<String>();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("Mazda");

    Collections.sort(cars, Collections.reverseOrder()); // Sort cars

    for (String i : cars) {
      System.out.println(i);
    }
  }
}

Butun sonlardan (Integer) iborat ArrayList’ni son qiymati bo‘yicha teskari (kamayish) tartibida saralang:

import java.util.ArrayList;
import java.util.Collections;  // Import the Collections class

public class Main {
  public static void main(String[] args) {
    ArrayList<Integer> myNumbers = new ArrayList<Integer>();
    myNumbers.add(33);
    myNumbers.add(15);
    myNumbers.add(20);
    myNumbers.add(34);
    myNumbers.add(8);
    myNumbers.add(12);

    Collections.sort(myNumbers, Collections.reverseOrder()); // Sort myNumbers

    for (int i : myNumbers) {
      System.out.println(i);
    }
  }
}