Collection: Sort to list Element, Convert Array to List, Covertion List to Array, Use of Iterator , Add collection in List

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;


public class List1
{

public static void main(String a[])
{
List<Integer> l1= new ArrayList<Integer>();
l1.add(21);
l1.add(2);
l1.add(54);

System.out.println( "total no of list elements:\n"+l1.size());
System.out.println(l1);


List<Integer> l2= new ArrayList<Integer>();
   l2.add(211);
l2.add(211);
l2.add(5411);
System.out.println("Add the another collection in list\n");
l1.addAll(l2);
System.out.println( "After Addition of additional collection  in List, Size of list:\n"+l1.size());
System.out.println(l1);
//l1.retainAll(l2);




System.out.println( "verify list  contains  additional collection \n");
        if (l1.containsAll(l2))
System.out.println(true);

else
System.out.println(false);


System.out.println("sort the data of array\n");
Collections.sort(l1);


//clear the Element of the Array
    //l1.clear();



System.out.println("Iterate the Element of List\n");
Iterator<Integer> i1=l1.iterator();
while(i1.hasNext())
{
System.out.println(i1.next());
}



System.out.println("list to Array Conversion\n");
       Integer[] intArray=l1.toArray(new Integer[l1.size()]);
       for (Integer i : intArray)
       {
        System.out.println(i);
   }
     
     
       System.out.println("Array  to List Conversion\n");
    List<Integer> listOfArray=Arrays.asList(intArray);
    System.out.println(listOfArray);



}

}

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Output:

total no of list elements:

3

[21, 2, 54]

Add the another collection in list

After Addition of additional collection  in List, Size of list:

6

[21, 2, 54, 211, 211, 5411]

verify list  contains  additional collection 

true

sort the data of array

Iterate the Element of List

2

21

54

211

211

5411

list to Array Conversion

2

21

54

211

211

5411

Array  to List Conversion

[2, 21, 54, 211, 211, 5411]