import java.util.ArrayList;

import java.util.Date;

import java.util.Iterator;

import java.util.List;

public class Demo {

    public static void main(String[] args) {

                        List<String> list = new ArrayList<>();

                        list.add("1234");

                        list.add("true");

                        list.add("aaaa");

                        list.add("aaaa");

                        list.add("bbbb");

                        list.add("dddd");  

                        String e3 = list.get(3);

                        System.out.println(e3);

                        System.out.println(list.get(3));

                        int size = list.size();

                        System.out.println(size);  

                        for (String item : list) {

                            System.out.println(item);

                        }  

                        System.out.println("--------------------------");

                        // Iterator迭代器

                        Iterator<String> iterator = list.iterator();

                        while (iterator.hasNext()) {// 判断是否还有下一个元素，有的话返回true

                            String next = iterator.next();// 取出元素，同时将指针指向当前位置

                            System.out.println(next);

                        }

                    }

} 

aaaa

aaaa

6

1234

true

aaaa

aaaa

bbbb

dddd

--------------------------

1234

true

aaaa

aaaa

bbbb

dddd