Looping ArrayList

Here are the three ways to loop through the ArrayList.

import java.util.*;
import java.lang.*;

class Rextester
{ 
    public static void main(String args[])
    {
        List<Integer> list = new ArrayList<Integer>();
        list.add(10);
        list.add(20);
       
        for(int i=0;i<list.size();i++)
        {
            System.out.println(list.get(i));
        }
       
        for(Integer num : list)
        {
            System.out.println(num);
        }
       
        Iterator<Integer> it = list.iterator();
        while(it.hasNext())
        {
            System.out.println(it.next());
        }
    }
}