Java ArrayList set方法

package com.codingdict;

import java.util.ArrayList;

public class ArrayListDemo {
   public static void main(String[] args) {

      // create an empty arraylist with an initial capacity
      ArrayList<Integer> arrlist = new ArrayList<Integer>(5);

      // use add() method to add elements in the list
      arrlist.add(15);
      arrlist.add(20);
      arrlist.add(25);
      arrlist.add(22);

      // let us print all the elements available in list
      for (Integer number : arrlist) {
         System.out.println("Number = " + number);
      }

      // inserting elment 55 at 3rd position
      arrlist.set(2,55);

      // let us print all the elements available in list
      System.out.println("Printing new list:");
      for (Integer number : arrlist) {
         System.out.println("Number = " + number);
      }
   }
}