ArrayList与普通数组的区别

 import java.util.ArrayList;
 public class Shuzuqubie {
     public static void main(String[] args){
         String[] pig = new String[2];
         String a = new String("猪猪1");
         pig[0] = a;
         String b = new String("猪猪2");
         pig[1] = b;
         int pigSize = pig.length; //通过pig数组的length属性来获取长度
         System.out.println("猪猪数组的大小是："+pigSize);

         ArrayList<Shuzuqubie> pigList = new ArrayList<Shuzuqubie>();
         Shuzuqubie p1 = new Shuzuqubie();
         pigList.add(p1);
         Shuzuqubie p2 = new Shuzuqubie();
         pigList.add(p2);
         int theSize = pigList.size();
         System.out.println("猪猪集合的大小是："+theSize);
     }

 }