Java 数组删除元素2

import java.util.ArrayList;

public class ArrayListDemo {
   public static void main(String[] args) {
      ArrayList<Integer> arr = new ArrayList<Integer>(5);
      arr.add(20);
      arr.add(15);
      arr.add(30);
      arr.add(45);

      System.out.println("Size of list: " + arr.size());
      for (Integer number : arr) {
         System.out.println("Number = " + number);
      }
      arr.remove(2);
      System.out.println("Now, Size of list: " + arr.size());

      for (Integer number : arr) {
         System.out.println("Number = " + number);
      }
   }
}