从ArrayList中删除Item

Question

我有一个ArrayList假设list,它有8项AH,现在我想删除存储在int数组中的1,3,5位置项,list我该怎么做.

我正试图这样做

ArrayList<String> list = new ArrayList<String>();
list.add("A");
list.add("B");
list.add("C");
list.add("D");
list.add("E");
list.add("F");
list.add("G");
list.add("H");

int i[] = {1,3,5};

for (int j = 0; j < i.length; j++) {
    list.remove(i[j]);
}

但是在第一个项目删除后,数组的位置被更改,并且在下一次迭代中,它会删除错误的元素或给出异常.

Answer 1

在这种特定情况下,您应该按降序删除元素.第一个索引5,然后3,然后1.这将从列表中删除元素而没有不良副作用.

for (int j = i.length-1; j >= 0; j--) {
    list.remove(i[j]);
}

Answer 2

您可以删除ArrayList使用中的元素ListIterator,

ListIterator listIterator = List_Of_Array.listIterator();

 /* Use void remove() method of ListIterator to remove an element from List.
     It removes the last element returned by next or previous methods.
 */
listIterator.next();

//remove element returned by last next method
listIterator.remove();//remove element at 1st position
listIterator.next();
listIterator.next();
listIterator.remove();//remove element at 3rd position
listIterator.next();
listIterator.next();
listIterator.remove();//remove element at 5th position

Answer 3

 public void DeleteUserIMP(UserIMP useriamp) {
       synchronized (ListUserIMP) {
            if (ListUserIMP.isEmpty()) {
            System.out.println("user is empty");
        }  else {
            Iterator<UserIMP> it = ListUserIMP.iterator();
            while (it.hasNext()) {
                UserIMP user = it.next();
                if (useriamp.getMoblieNumber().equals(user.getMoblieNumber())) {
                    it.remove();
                    System.out.println("remove it");
                }
            }
            // ListUserIMP.remove(useriamp);

            System.out.println(" this user removed");
        }
        Constants.RESULT_FOR_REGISTRATION = Constants.MESSAGE_OK;
        // System.out.println("This user Deleted " + Constants.MESSAGE_OK);

    }
}

Answer 4

正如先前所说

iterator.remove()

可能是循环期间删除列表项的唯一安全方法.

要更深入地了解使用迭代器删除项目,请尝试查看此主题