Java get last element of a collection

前端 未结 10 824
你的背包
你的背包 2020-12-30 18:47

I have a collection, I want to get the last element of the collection. What\'s the most straighforward and fast way to do so?

One solution is to first toArray(), and

10条回答
  •  猫巷女王i
    2020-12-30 19:10

    A Collection is not a necessarily ordered set of elements so there may not be a concept of the "last" element. If you want something that's ordered, you can use a SortedSet which has a last() method. Or you can use a List and call mylist.get(mylist.size()-1);

    If you really need the last element you should use a List or a SortedSet. But if all you have is a Collection and you really, really, really need the last element, you could use toArray() or you could use an Iterator and iterate to the end of the list.

    For example:

    public Object getLastElement(final Collection c) {
        final Iterator itr = c.iterator();
        Object lastElement = itr.next();
        while(itr.hasNext()) {
            lastElement = itr.next();
        }
        return lastElement;
    }
    

提交回复
热议问题