public static void main(String[] args) {
        //length 、length()、size()的区别
        //length属性 针对数组长度
        String a[]={"zhangsan","lisi","wangwu","zhaoliu"};
        System.out.println(a.length);
        //length()方法 针对字符串
        String b="zhangsanlisiwangwuzhaoliu";
        System.out.println(b.length());
        //size()方法针对泛型集合
        List<String> person=new ArrayList();
        person.add("zhangsan");
        System.out.println(person.size());

    }
运行结果：

   4 

   25

  1