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);
    }

}