java中ArrayList使用remove注意事项

1、java 中 ArrayList 使用 remove 注意事项/ 在 remove 一条信息时，ArrayList 的大小已经改变(即 list.size() 已经改变)；在 i 大于等于 list.size() 时，循环跳出，后便的 ArrayList不能再执行；所以必须在 remove 的同时，执行 i- ，即 i=i-1 ； 现在才能遍历所有 List 中的信息。也不能在用 Iterator遍历时使用 remove, 会抛异常。public class TrickyAL publicstatic LinkedList<User> llu=newLinkedLi

2、st<User>();publicstatic HashMap<String,User> hmu=newHashMap<String,User>();publicstatic ArrayList<User> ulist=new ArrayList<User>(Arrays.asList(newUsernew User(2,"Eric"),new User(3,"Eric"),new User(1,"Aaro

3、n"),new User(4,"Eric");staticllu.add(new User(1,"Aaron");llu.add(new User(2,"Eric");llu.add(new User(3,"Tom");hmu.put("1",new User(3,"Tom");hmu.put("2",new User(2,"Eric");hmu.put("3",new User(1,"Leo&q

4、uot;);hmu.put("3",new User(4,"Scott");public static void deleteUser(ArrayList<User> urlist,String auser)int c=urlist.size();for(int i=0;i<c;i+)urlist.remove(i);c-;public static void deleteUser(LinkedList<User> urlist,String auser)int c=urlist.si

5、ze();for(int i=0;i<c;i+)urlist.remove(i);c-;public static void deleteUser(HashMap<String,User> urlist,String auser)intc=urlist.size();Iteratorhmi=urlist.entrySet().iterator();Stringks=""for(Stringsk : urlist.keySet()if(auser.equals(urlist.get(sk).name)System.out.printl

6、n(auser);ks=sk;break;urlist.remove(ks);publicstatic void main(String args) / TODO Auto-generated method stub/ArrayList mul=(ArrayList)ulist;System.out.println(ulist);/deleteUser(ulist,"Eric");/Arrays.sort(ulist.toArray();System.out.println(ulist);System.out.println("2->"+l

7、lu);Collections.reverse(llu);deleteUser(llu,"Eric");System.out.println(llu);System.out.println("3->"+hmu);deleteUser(hmu,"Eric");System.out.println(hmu);Collections.copy(ulist,llu );System.out.println(ulist);System.out.println(llu); public static class Userpublic int id;public String name;public User(int id,Str