Java ArrayList get方法

package com.codingdict;

import java.util.ArrayList;

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

      // create an empty array list 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(22);
      arrlist.add(30);
      arrlist.add(40);

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

      // retrieves element at 4th postion
      int retval=arrlist.get(3);
      System.out.println("Retrieved element is = " + retval);      
   }
}