/**
Author  : Michael Robinson
Program : arrayList_Iterators2.java
Purpose : How to create a Java ArrayList using Iterators.
          Shows how to add elements to an ArrayList
          How to delete items 
          How to get and print data items using for loops.
       
Updated : July 2nd, 2012
*/
    

import java.util.ArrayList;
import java.util.Iterator;

public class arrayList_Iterators2 
{
    public static void alphaArrayList()
    {
        System.out.println("------------------------------------------");
        System.out.println(" Processing ArrayList of String data type");
        System.out.println("           using ITERATORS               ");        
        System.out.println("------------------------------------------");
      
        System.out.println(" Creating ArrayList...");

        //create an ArrayList object
        ArrayList<String> arrayList = new ArrayList<String>();

        System.out.println(" Adding data elements to the ArrayList...");
        //Add elements to Arraylist using
         arrayList.add("a");
        arrayList.add("b");
        arrayList.add("c");
        arrayList.add("d");
        arrayList.add("e");
        arrayList.add("f");
     
        System.out.println("\n Getting data elements from the ArrayList");
        System.out.println(" Iterating through ArrayList elements...");

        //This is a loop type class which allows to loop thru the ArrayList
        Iterator<String> itr = arrayList.iterator();

        //use hasNext() and next() methods of Iterator to iterate through the ArrayLis
        while(itr.hasNext())
        {
           System.out.print(" "+itr.next());
        }
        
        //now remove elements !!! always remove from the highest to the lowest location
        System.out.println("\n\n Removing data elements from the ArrayList on index 3 = "
                     + arrayList.get(3) +
                       "\n                                          and index 1 = " +
                       arrayList.get(1) );
        
        arrayList.remove(3);
        arrayList.remove(1);

        System.out.println();
        System.out.println(" Getting data elements from the ArrayList after removing");
        System.out.println(" Iterating through ArrayList elements...");

        itr = arrayList.iterator(); //reset iterator to beginning of ArrayList
        
        //use hasNext() and next() methods of Iterator to iterate through the ArrayLis
        while(itr.hasNext())
        {
           System.out.print(" "+itr.next());
        }

        System.out.println("\n\n");
      
    }//end public static void alphaArrayList()

    
    public static void numericArrayList()
    {
        System.out.println("------------------------------------------");
        System.out.println(" Processing ArrayList of Integer data type");
        System.out.println("           using ITERATORS                ");
        System.out.println("------------------------------------------");
        
        System.out.println(" Creating ArrayList...");
        //create an ArrayList object
        ArrayList<Integer> arrayList = new ArrayList<Integer>();
     
        System.out.println(" Adding data elements to the ArrayList...");        
         //Add elements to Arraylist using
        arrayList.add(1100);
        arrayList.add(2100);
        arrayList.add(3100);
        arrayList.add(4100);
        arrayList.add(5100);
        arrayList.add(6100);
     
        System.out.println("\n Getting data elements in the ArrayList");
        System.out.println(" Iterating through ArrayList elements...");

        //This is a loop type class which allows to loop thru the ArrayList
        Iterator<Integer> itr = arrayList.iterator();

        //use hasNext() and next() methods of Iterator to iterate through the ArrayLis
        while(itr.hasNext())
        {
           System.out.print(" "+itr.next());
        }
         
        System.out.println("\n\n Removing data elements from the ArrayList on index 3 = "
                       + arrayList.get(3) +
                       "\n                                          and index 1 = " +
                       arrayList.get(1) );

        //now remove some !!! always remove from the height to the lowest
        arrayList.remove(3);
        arrayList.remove(1);

        System.out.println("\n Getting data elements from the ArrayList after removing");
        System.out.println(" Iterating through ArrayList elements...");

        itr = arrayList.iterator(); //reset iterator to beginning of ArrayList
        
        //use hasNext() and next() methods of Iterator to iterate through the ArrayList
        while(itr.hasNext())
        {
           System.out.print(" "+itr.next());
        }
        System.out.println();
        
    }//end public static void numericArrayList()
    
    
    public static void addNextRemoveIterator()
    {
        System.out.println("------------------------------------------");
        System.out.println(" Processing ArrayList of String data type");
        System.out.println("           using ITERATORS               ");        
        System.out.println("------------------------------------------");
      
        System.out.println(" Creating ArrayList...");

        //create an ArrayList object
        ArrayList<String> arrayList = new ArrayList<String>();

        System.out.println(" Adding data elements to the ArrayList...");
        //Add elements to Arraylist using
        arrayList.add("A");
        arrayList.add("B");
        arrayList.add("C");
        arrayList.add("D");
        arrayList.add("E");
        arrayList.add("F");
     
        System.out.println("\n Getting data elements from the ArrayList");
        System.out.println(" Iterating through ArrayList elements...");

        //This is a loop type class which allows to loop thru the ArrayList
        Iterator<String> itr = arrayList.iterator();

        String temp = "";
        //use hasNext() and next() methods of Iterator to iterate through the ArrayLis
        while( itr.hasNext() )
        {
            if( itr.hasNext() )
            {
                System.out.println( "\n\n itr.hasNext() = " + itr.hasNext() );
                temp = itr.next();
                System.out.println( " itr.next() = " + temp );
                System.out.println( " removing =   " + temp );                
                itr.remove();                
            }
            else
            {
                System.out.println( "\n ***The Arraylist is empty itr.hasNext() = [" +
                                     itr.hasNext() + "]" );
            }

        }
        
        if( itr.hasNext() )
        {
            System.out.println( "\n itr.hasNext() = " + itr.hasNext() );
        }
        else
        {
            System.out.println( "\n itr.hasNext() = [" + itr.hasNext() + "]" );
            System.out.println( " The Arraylist is empty itr.hasNext() = [" + itr.hasNext() + "]" );

        }

        System.out.println();
        System.out.println(" Getting data elements from the ArrayList after removing");
        System.out.println(" Iterating through ArrayList elements...");

        itr = arrayList.iterator(); //reset iterator to beginning of ArrayList
        
        //use hasNext() and next() methods of Iterator to iterate through the ArrayLis
        while(itr.hasNext())
        {
           System.out.print(" "+itr.next());
        }

        System.out.println("\n\n");
      
    }//end public static void addNextRemoveIterator()


    public static void main(String[] args) 
    {
        alphaArrayList();
        numericArrayList();
        addNextRemoveIterator();
    }
    
}