Asosiy bash Java ArrayList usullari bilan misollar

Java ArrayList usullari bilan misollar

Ushbu postda biz eng keng tarqalgan Java ArrayList usullarini har bir usul uchun kod misollari bilan yoritamiz.

ArrayList class - o'lchamlari o'zgaruvchan qator. Biz odatda ArrayList dan foydalanamiz ro'yxatning hajmini oldindan bilmaganimizda.

ArrayList sinf java.util paket.

ArrayList-ni qanday yaratish kerak

ArrayList yaratish va unga elementlarni qo'shish uchun biz ArrayList ni o'rnatamiz String kabi belgilangan turga ega ob'ekt yoki Integer.

add() Ga e'tibor bering usuli elementni ArrayList-ning keyingi holatiga qo'shadi. Ob'ektni ma'lum bir indeksga qanday qo'shishni ko'rish uchun keyingi misolga qarang.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket);   } }

Chiqish:

[Apple, Banana, Grapes, Orange]

Qanday qilib ma'lum bir pozitsiyaga element qo'shish kerak

Ob'ektni belgilangan joyga qo'shish uchun add() ga kerakli indeksni taqdim etishimiz kerak usul.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
fruitBasket.add(2, 'Melon');
System.out.println(fruitBasket);   } }

Chiqish:

[Apple, Banana, Melon, Grapes, Orange]

ArrayList-dagi elementga qanday kirish mumkin

get() usuli elementni oladi. Indeks raqamini get() ga berishimiz kerak usul.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket.get(1));   } }

Banana

ArrayList ro'yxatidan elementni qanday olib tashlash mumkin

Elementni olib tashlash uchun biz remove() dan foydalanamiz usul. Indeks raqamini ko'rsatishimiz kerak.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
fruitBasket.remove(0);
System.out.println(fruitBasket);   } }

Chiqish:

[Banana, Grapes, Orange]

ArrayList ro'yxatidan barcha narsalarni qanday olib tashlash mumkin

clear() usuli barcha elementlarni ArrayList dan o'chirib tashlaydi.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
fruitBasket.clear();
System.out.println(fruitBasket);   } }

[]

ArrayList hajmini qanday olish mumkin

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket.size());   } }

Chiqish:

4

ArrayList orqali qanday ko'chirish mumkin

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
for (int i = 0; i < fruitBasket.size(); i++) {
  System.out.println(fruitBasket.get(i));
}   } }

Chiqish:

Apple Banana Grapes Orange

Har biri uchun ArrayList orqali ko'chadan o'tish

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
for (String i : fruitBasket) {
  System.out.println(i);
}   } }

Chiqish:

Apple Banana Grapes Orange

ArrayList misoli raqamlar bilan

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList numbers = new ArrayList();
numbers.add(10);
numbers.add(20);
numbers.add(30);
numbers.add(40);
for (int i : numbers) {
  System.out.println(i);
}   } }

Chiqish:

10 20 30 40

ArrayList-dagi elementni qanday almashtirish mumkin

replace() usuli elementni boshqa taqdim etilgan element bilan almashtiradi. O'zgartirmoqchi bo'lgan narsaning indeksini ko'rsatishimiz kerak.

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
 fruitBasket.set(3, 'Peach')
for (String i : fruitBasket) {
  System.out.println(i);
}   } }

Chiqish:

#before replace [Apple, Banana, Grapes, Orange] #after replace [Apple, Banana, Grapes, Peach]

ArrayList-dagi narsalarni qanday aralashtirish mumkin

shuffle() usuli Collections da class va ArrayList elementlarini tasodifiy aralashtirish uchun ishlatiladi.

import java.util.ArrayList;  import java.util.ArrayList; import java.util.Collections;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket);
 Collections.shuffle(fruitBasket);
System.out.println(fruitBasket);   } }

Chiqish:

#before shuffle [Apple, Banana, Grapes, Orange] #after shuffle [Grapes, Orange, Banana, Apple]

ArrayList-dagi elementlarni qanday saralash mumkin

import java.util.ArrayList;  import java.util.ArrayList; import java.util.Collections;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Orange');
fruitBasket.add('Apple');
fruitBasket.add('Grapes');
fruitBasket.add('Banana');
System.out.println(fruitBasket);
 Collections.sort(fruitBasket);
System.out.println(fruitBasket);   } }

Chiqish:

#before sort [Orange, Apple, Grapes, Banana] #after sort [Apple, Banana, Grapes, Orange]

ArrayList-dagi narsalarni qanday o'zgartirish mumkin?

public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket);
 Collections.reverse(fruitBasket);
System.out.println(fruitBasket);   } }

Chiqish:

#original list [Apple, Banana, Grapes, Orange] #after reverse [Orange, Grapes, Banana, Apple]

ArrayListni qanday qilib massivga aylantirish mumkin

 import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
 String[] fruitArray = new String[fruitBasket.size()];
fruitBasket.toArray(fruitArray);
 for (String i : fruitArray) {
  System.out.println(i);
}   } }

Chiqish:

Apple Banana Grapes Orange

ArrayList-da ikkita narsani qanday almashtirish mumkin

import java.util.ArrayList; import java.util.Collections;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket = new ArrayList();
fruitBasket.add('Apple');
fruitBasket.add('Banana');
fruitBasket.add('Grapes');
fruitBasket.add('Orange');
System.out.println(fruitBasket1);
 Collections.swap(fruitBasket, 1, 3);
System.out.println(fruitBasket);   } }

Chiqish:

#before swap [Apple, Banana, Grapes, Orange] #after swap [Apple, Orange, Grapes, Banana]

Ikki qatorli ro'yxatga qanday qo'shilish mumkin

import java.util.ArrayList;  public class ArrayListTutorial {   public static void main(String[] args) {
ArrayList fruitBasket1 = new ArrayList();
ArrayList fruitBasket2 = new ArrayList();
 fruitBasket1.add('Apple');
fruitBasket1.add('Banana');
fruitBasket1.add('Grapes');
fruitBasket1.add('Orange');
 fruitBasket2.add('Melon');
fruitBasket2.add('Strawberries');
 fruitBasket1.addAll(fruitBasket2);
 System.out.println(fruitBasket1);   } }

Chiqish:

[Apple, Banana, Grapes, Orange, Melon, Strawberries]