Algoritmlash asoslari

public class LinkedHashSetExample {

 

public static void main(String args[]) {

 

// LinkedHashSet of String Type

 

LinkedHashSet<String> lhset = new LinkedHashSet<String>(); // Adding elements to the LinkedHashSet lhset.add("Z");

 

lhset.add("PQ");

 

lhset.add("N");

 

lhset.add("O");

 

lhset.add("KK");

 

lhset.add("FGH");

 

System.out.println(lhset); // LinkedHashSet of Integer Type

 

LinkedHashSet<Integer> lhset2 = new LinkedHashSet<Integer>(); // Adding elements lhset2.add(99);

 

lhset2.add(7);

 

lhset2.add(0);

 

lhset2.add(67);

 

lhset2.add(89);

 

lhset2.add(66);

 

System.out.println(lhset2); }}

Ekaranda:

[Z, PQ, N, O, KK, FGH]

[99, 7, 0, 67, 89, 66]

Ko’rib turganingizdek elementlarni saqlash tartibida qaytaryapti(ekranga chiqaryapti).

@tuit_online kanali sizlar uchun maxsus...
26-dars - Javada Map
Map ham to'plam bo'lib, boshqalaridan farqi key(kaliti) ham ob’yekt saqlay olishidadir. Map'da key hech qachon dublikat(takror) bo'lishi mumkin emas. Map interface bo'lib undan HashMap, TreeMap LinkedHashMap'lar implement oladi.
HashMap klassi

HashMap asosi Map interface bo'lgan to'plam(collection) bo'lib, u o'zida juft qiymatlardan foydalanadi ular key(kalit) va value(qiymat)dir. Bu klass elementlarni saqlanish tartibida saqlamaydi. Huddi HashTable klassiga o'xshab ketadi. U sinxron emas, o'zida key(kalit)ini ham value(qiymat)ini ham null qiymat saqlashi mumkin. HashMap'da faqat bitta null key(kalit) saqlash mumkin.

E'lon qilinishi: HashMap


HahshMap'ga misol:

Source code

import java.util.HashMap;

import java.util.Map;

import java.util.Iterator;

import java.util.Set;

public class Details {

public static void main(String args[]) {

/* Bu misol HashMap'ning qanday e'lon qilishi */

HashMap<Integer, String> hmap = new HashMap<Integer, String>();

/*HashMap'ga elementlar qo'shish*/

hmap.put(12, "Aziz");

hmap.put(2, "Zafar");

hmap.put(7, "Jalol");

hmap.put(49, "Fayzullo");

hmap.put(3, "Jamshid");

/* Iterator kontentini ko'rsatish*/

Set set = hmap.entrySet();

Iterator iterator = set.iterator();

while(iterator.hasNext()) {

Map. HYPERLINK "http://www.google.com/search?hl=en&q=allinurl%3Amap.entry+java.sun.com&btnI=I%27m%20Feeling%20Lucky"Entry mentry = (Map. HYPERLINK "http://www.google.com/search?hl=en&q=allinurl%3Amap.entry+java.sun.com&btnI=I%27m%20Feeling%20Lucky"Entry)iterator.next();

System.out.print("key is: "+ mentry.getKey() + " & Value is: ");

System.out.println(mentry.getValue());

}

/* key orqali elementni olish

String var= hmap.get(2);

System.out.println("Value at index 2 is: "+var);

/* key orqali elementni o’chirish*/

hmap.remove(3);

System.out.println("Map key and values after removal:");

Set set2 = hmap.entrySet();

Iterator iterator2 = set2.iterator();

while(iterator2.hasNext()) {

Map. HYPERLINK "http://www.google.com/search?hl=en&q=allinurl%3Amap.entry+java.sun.com&btnI=I%27m%20Feeling%20Lucky"Entry mentry2 = (Map. HYPERLINK "http://www.google.com/search?hl=en&q=allinurl%3Amap.entry+java.sun.com&btnI=I%27m%20Feeling%20Lucky"Entry)iterator2.next();

System.out.print("Key is: "+mentry2.getKey() + " & Value is: ");

System.out.println(mentry2.getValue());

}

}

}
Ekranda:

Source code

key is: 49 & Value is: Fayzullo

key is: 2 & Value is: Zafar

key is: 3 & Value is: Jamshid

key is: 7 & Value is: Jalol

key is: 12 & Value is: Aziz

Map key and values after removal:

Key is: 49 & Value is: Fayzullo

Key is: 2 & Value is: Zafar

Key is: 7 & Value is: Jalol

Key is: 12 & Value is: Aziz
HashMap'ni elementlarni olishining ikki xil usuli bor

• 
  For loop orqali
  
• 
  While loop + iterator
  

misol:

import java.util.HashMap;

import java.util.Map;

import java.util.Iterator;

public class Details

{

public static void main(String [] args)

{

HashMapString> hmap = new HashMapString>();

// HashMap'ga elementlarni qo'shish

hmap.put(11, "AB");

hmap.put(2, "CD");

hmap.put(33, "EF");

hmap.put(9, "GH");

hmap.put(3, "IJ");

// FOR sikli

System.out.println("For Loop:");

for (Map.Entry me : hmap.entrySet()) {

System.out.println("Key: "+me.getKey() + " & Value: " + me.getValue());

}

//WHILE sikli & ITERATOR

System.out.println("While Loop:");

Iterator iterator = hmap.entrySet().iterator();

while (iterator.hasNext()) {

Map.Entry me2 = (Map.Entry) iterator.next();

System.out.println("Key: "+me2.getKey() + " & Value: " + me2.getValue());

}

}

}

ekranda:

For sikli:

Key: 2 & Value: CD

Key: 3 & Value: IJ

Key: 33 & Value: EF

Key: 9 & Value: GH

Key: 11 & Value: AB

While sikli:

Key: 2 & Value: CD

Key: 3 & Value: IJ

Key: 33 & Value: EF

Key: 9 & Value: GH

Key: 11 & Value: AB
HashMap'ni key orqali saralash

Bu misolda HashMap'ning key'ini TreeMap'dan foydalanib saralash usulini ko'ramiz.
import java.util.HashMap;

import java.util.Map;

import java.util.TreeMap;

import java.util.Set;

import java.util.Iterator;

public class Details {

public static void main(String[] args) {

HashMapString> hmap = new HashMapString>();

hmap.put(5, "A");

hmap.put(11, "C");

hmap.put(4, "Z");

hmap.put(77, "Y");

hmap.put(9, "P");

hmap.put(66, "Q");

hmap.put(0, "R");

System.out.println("Saralashdan oldin:");

Set set = hmap.entrySet();

Iterator iterator = set.iterator();

while(iterator.hasNext()) {

Map.Entry me = (Map.Entry)iterator.next();

System.out.print(me.getKey() + ": ");

System.out.println(me.getValue());

}

MapString> map = new TreeMapString>(hmap);

System.out.println("Saralashdan keyin:");

Set set2 = map.entrySet();

Iterator iterator2 = set2.iterator();

while(iterator2.hasNext()) {

Map.Entry me2 = (Map.Entry)iterator2.next();

System.out.print(me2.getKey() + ": ");

System.out.println(me2.getValue());

}

}

}

Ekranda: