如何在Java中查找链表中元素的索引之一是否为零

Question

I have a linked list. An item may be at several indexes of this list (eg index 0, index 3, and index 5). How can I find if one of these indexes is index 0; I need that because I use some formulas to calculate some values, and the formula is different if one position of the item is index 0.

Answer 1

您可以检查第一个元素是您想要的对象

if (list != null && list.size() > 0 && list.get(0).equals(element))

Answer 2

You can use the get method on list and the equals method on your item

list.get(0).equals(myItem);

Normally you don't want to use get(int) on a LinkedList because it's an order n traversal. But index 0 will always be at the front and is a very short traversal. :)