/*
  Author  : Michael Robinson
  Program : arrayToArrayListAndBack.java
  Purpose : How to copy Array's data to an ArrayList
            Modify the ArrayList
            Copy ArrayList data to a new Array 
  
  Updated : December 10, 2099
*/


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


public class arrayToArrayListAndBack 
{
    public static void arraysToListAndBack() 
    {
        //create Array array1
        System.out.println( "-Creating Array array1" );
        String array1[] = { "one ","square","two ", "three", "cube",
                            "seven" };
          
        //create an ArrayList object
        System.out.println("-Creating ArrayList list1");
        ArrayList<String> list1 = new ArrayList<String>();
         
        //add Array array1 to ArrayList list1
	   System.out.println( "\n-Copying Array array1 to" +
                            " ArrayList list" );
	   for( String elements : array1 )
	   {
	       list1.add( elements );
	       System.out.printf( " %s", elements );
	   }
	      	
        //create another Array array2
	   System.out.println( "-Creating Array array2" );
	   String array2[] = { "four", "triangle", "five", "cone", 
                            "six", "eight" };
       
	   //add Array array2 to ArrayList list1
	   System.out.println( "\n-Copying Array array2 to " +  
                            "ArrayList list" );

 	   for( String elements : array2 )
	   {
	       list1.add( elements );
            System.out.printf( " %s", elements );
	   }
	   System.out.println( "\n" );
        
	   //create Iterator itr to travel through the Arraylist
        //list
	   System.out.println( "-Create Iterator itr to " +
                            "travel through the Arraylist list" );

	   Iterator<String> itr = list1.iterator();
	               

	   //use hasNext() and next() methods of Iterator to
        //iterate through the elements
	   System.out.println( "-Iterating through ArrayList " + 
                            "list1 elements..." );

	   while( itr.hasNext() )
	   {
	       System.out.print( " " + itr.next() );
	   }
	   System.out.println( "\n" );
	         	
	   System.out.println( "- Using the new Iterator itr2 we copy" +
                            " the elements in the even locations " +
                            "\n to a new array of length 10 called" +
                            "array3, and the elements in the odd " + 
                            "locations to a new array of length 10" +
                            " called array4" );
 	                         
        System.out.println( "\n- Create Iterator itr2 to travel" +
                            " thru the Arraylist list." +
                            "\n In Java Iterators can NOT be reset" +
                            " to the beginning of the list " +
	                       "\n to travel the list again we must " +
                            "create a new Iterator." );
            
	   //create a new iterator itr2 to copy element to new bigger
        //arrays
	   Iterator<String> itr2 = list1.iterator();
	    
	   System.out.println( "\n-Creating two new arrays of length" +
                            " 10 each. array3 and array4" );
        //create two arrays of size 10 each
        String array3[] = new String[ 10 ];
        String array4[] = new String[ 10 ];
          
        System.out.println( "\n-Copying even elements in list1 to" +
                            " array3 and odd elements to array4" );
 
        //copy even elements in list1 to array3 and odd elements 
        //to array4
        int x = 0; 
        int y = 0;
        int z = 0; 
        
        while( itr2.hasNext() )
	   {
	       if( (x % 2) == 0 ) //copy even elements in list to array3
	       {	
	           array3[z] =  itr2.next();
	    	      System.out.print( " array3[" + z + "] = " +
                array3[z] + "\t" );
                  
                z++;
	       }
	       else //copy odd elements in list to array4
	       {
	    	      array4[y] =  itr2.next();
	           System.out.println( "array4[" + y + "] = " +
                                    array4[y]);
	    	      y++; 
	       }
	       x++;
	   }
	 	
	   z = 0;
	   System.out.println( "\n-Displaying the elements in list1" +
		                  " of length " + list1.size() );
            
	   for( x = 0; x < list1.size(); x++ )
	   {
	       System.out.print( " " + list1.get(x) + "\t" );
	       z++;
	       if( z == 2 )
	       {
	           System.out.println();
	           z = 0;
	  	  }
        }
 	 	
	   z = 0;		
	   System.out.println( "\n-Displaying the elements in array3" +
	                       " of length " + array3.length);
        
	   for( x = 0; x < array3.length; x++ )
	   {
	       System.out.print( " " + array3[x] + "\t" );
            z++;

	       if( z == 2 )
	       {
	           System.out.println();
	           z = 0;
	       }
	   }
       
	   z = 0;

	   System.out.println( "\n-Displaying the elements in array4" );
           
	   for( x = 0; x < array4.length; x++ )
	   {
	       System.out.print( " " + array4[x] + "\t" );
            z++;

	       if( z == 2 )
            {
	           System.out.println();
	           z = 0;
	       }
	   }

        System.out.println( "\n" );
        
    }//end arraysToListAndBack()
     
  
    public static void main( String arg[] )
    {
        arraysToListAndBack(); 
    }
    
}//end public class arrayToArrayListAndBack