RandomAccess

接口作用

實作該接口，就說明支援随機通路方式周遊

例子

public static void main(String[] args)  {
        ArrayList<String> list = new ArrayList<>();
        if (list instanceof RandomAccess) {
            //随機通路
            for (int i = 0; i < list.size(); i++) {
                System.out.println(list.get(i));
            }
        } else {
            //疊代器通路
            Iterator<String> iterator = list.iterator();
            while (iterator.hasNext()) {
                System.out.println(iterator.next());
            }
        }
    }