List

Članek govori o podatkovni strukturi List v programskem jeziku Java.

Podatkovna struktura List (Seznam) predstavlja splošno zaporedje objektov:

• pojem pozicije
• dodajanje in izločanje objektov v predvidenem času

Collection Framework vsebuje:

• vmesnik List
• dva abstraktna razreda: AbstractList in AbstractSequentialList
• več realiziranih razredov: LinkedList, ArrayList, Vector
• iterator ListIterator

Primer

import java.util.*;
 
public class Seznam
{ 
  public static void main(String[] args)
    { 
      String[] avti = {"BMW","Ford","Yugo","Audi","Fiat","Renault","Pegueot","Seat","Citroen"};
      List sez = Arrays.asList(avti); //ustvarimo List iz Arraya stringov avti
 
      System.out.println("sez = " + sez);
      System.out.println("sez.size() = " + sez.size());
      System.out.println("sez.getClass().getName() = "+ sez.getClass().getName());
      System.out.println("sez.get(1) = " + sez.get(1));
      System.out.println("sez.contains(\"BMW\") = "+ sez.contains("BMW"));
 
      List podsez = sez.subList(2,7);
 
      System.out.println("podsez = " + podsez);
 
      Object object = podsez.get(1);
 
      System.out.println("podsez.get(1) = " + object);
 
       System.out.println("podsez.contains(\"BMW\") = "+ podsez.contains("BMW"));
      //podsez.remove(3);
 
         ListIterator it = podsez.listIterator();
 
      System.out.println("it.next() = " + it.next());
      System.out.println("it.next() = " + it.next());
      System.out.println("it.next() = " + it.next());
      System.out.println("it.next() = " + it.next());
      System.out.println("it.previous() = " + it.previous());
      System.out.println("it.previous() = " + it.previous());
      //it.add("Volkswagen");
 
      ArrayList Tsez=new ArrayList();
 
      ListIterator it1 = sez.listIterator();
 
      while (it1.hasNext())
         Tsez.add(it1.next());
 
       System.out.println("Tsez = " + Tsez);
 
      System.out.println("Pozicija= " + it1.nextIndex());     
 
      LinkedList Lsez=new LinkedList(Tsez);
 
       System.out.println("Lsez = " + Lsez);
      System.out.println("Lsez.getClass().getName() = "+ Lsez.getClass().getName());
 
      while (it1.hasPrevious())
        Lsez.addFirst(it1.previous());
 
       System.out.println("Lsez = " + Lsez);
 
         System.out.println("Prvi element = " + Lsez.getFirst());        
         System.out.println("Zadnji element = " + Lsez.getLast());        
 
         System.out.println("Brisem prvi element");
         Lsez.removeFirst();        
         System.out.println("Brisem zadnji element ");
         Lsez.removeLast();        
 
      System.out.println("Lsez = " + Lsez);
 
       System.out.println("Brisem celoten Lsez...");
 
      ListIterator it2 = Lsez.listIterator();     
      while (it2.hasNext())
      { 
         System.out.println("Pozicija = " + it2.nextIndex());
         //System.out.println("Element = " + it2.next());        
          //it2.remove();
         System.out.println("Element = " + Lsez.getFirst());        
           Lsez.removeFirst();         
      } 
       System.out.println("Lsez = " + Lsez);
 
       System.out.println("Brisem celoten Tsez...");
 
      ListIterator it3 = Tsez.listIterator();     
      while (it3.hasNext())
      { 
         System.out.println("Pozicija = " + it3.nextIndex());
        System.out.println("Element = " + it3.next());        
          it3.remove();
         //System.out.println("Element = " + Tsez.get(0));        
          //Tsez.remove(0);          
      } 
       System.out.println("Tsez = " + Tsez);
 
  }
}