How to use Vector in Java with example ?.

Program to demonstrate how to implement Vector class in java.util.*; package along with its operations :

package com.hubberspot.collections.example;

import java.util.*;

public class VectorExample 
{
  public static void main(String args[]) 
  {
    Vector vector = new Vector(3, 2);
      
    System.out.println("Initial size: " + vector.size());
    System.out.println("Initial capacity: " +
      
    vector.capacity());
      
    vector.addElement(new Integer(3));
    vector.addElement(new Integer(4));
    vector.addElement(new Integer(5));
    vector.addElement(new Integer(6));
      
    System.out.println("Capacity after adding 4 elements: " +
          vector.capacity());

    vector.addElement(new Double(6.35));
      
    System.out.println("Current capacity: " +
          vector.capacity());
      
    vector.addElement(new Double(7.98));
    vector.addElement(new Integer(8));
     
    System.out.println("Current capacity: " +
          vector.capacity());
      
    vector.addElement(new Float(10.4));
    vector.addElement(new Integer(11));
      
    System.out.println("Current capacity: " +
      vector.capacity());
      
    System.out.println("First element: " +
         vector.firstElement());
      
    System.out.println("Last element: " +
         vector.lastElement());
     
    System.out.println("\nElements in vector: " + vector);
      
   }
}

Output of the program :

How to implement ListIterator Interface in Java Collections ?.

Program to demonstrate implementation of ListIterator Interface in Java Collections

package com.hubberspot.collections.example;

import java.util.*;

public class ListIteratorExample
{
 public static void main(String[] args)
 {
  LinkedList list = new LinkedList();
  
  list.add("One");
  list.add("Two");
  list.add("Three");
  list.add("Four");
  
  ListIterator iterator = list.listIterator();
  
  while(iterator.hasNext())
  {     
 String element = (String)iterator.next();
 System.out.println(element);
    iterator.set("Number " + element);
  }  
 
  
  System.out.println("Traversing Backwards : ");
 
  while(iterator.hasPrevious())
    System.out.println(iterator.previous()); 
  }
 
}

Output of the program :

How to perform operations of Union and Intersection on two or more LinkedList in Java ?.

Program to demonstrate Union and Intersection of two LinkedList in Java

package com.hubberspot.collections.example;

import java.util.*;
import java.io.*;

public class LinkedListOperationsDemo
{
  static BufferedReader br = new BufferedReader
   (new InputStreamReader(System.in));

  public static void main(String args[]) throws IOException
  {
    LinkedList list1 = new LinkedList();
    LinkedList list2 = new LinkedList();
    LinkedList list3 = new LinkedList();
    LinkedList list4 = new LinkedList();
   
    int num1, num2;

    System.out.print("Enter no.of Elements in list 1:");
  
    num1 = Integer.parseInt(br.readLine());

    System.out.println("Enter Elements of list 1");
  
    for(int i=1; i <= num1; i++)
    {
      System.out.print("Enter Element "+i+": ");
      String element = br.readLine();
 
      if(!list1.contains(element))
 list1.add(element);
    }                                

    System.out.print("Enter no.of Elements in list 2:");
  
    num2 = Integer.parseInt(br.readLine());
  
    System.out.println("Enter Elements of list 2");
  
    for(int i=1; i <= num2; i++)
    {
      System.out.print("Enter Element "+i+": ");
      String element = br.readLine();
 
      if(!list2.contains(element))
 list2.add(element);
    }                                

    Collections.sort(list1);
    Collections.sort(list2);

    System.out.println("List 1:"+list1);
    System.out.println("List 2:"+list2);
     
    for(int i=0; i < list1.size(); i++)
      list3.add(list1.get(i));
  
    for(int i=0; i < list2.size(); i++)
      if(!list1.contains(list2.get(i)))
 list3.add(list2.get(i));
  
    System.out.println("Union: "+list3);
  
    for(int i=0; i < list1.size(); i++)
       list4.add(list1.get(i));
  
    list4.retainAll(list2);
  
    System.out.println("Intersection: "+list4);

   }
}

Output of the program :