一個無限的迭代器完全做你上面的代碼,除了當它碰到結束元素時回退。
也許這個例子將有助於說明它會如何派上用場:
Let l = [1,2,3,4,5,6,7,8]
int i = 0;
InfiniteIterator itr = l.infiniteIterator();
while(itr.hasNext()) {
if(i % 2 == 0) {
itr.remove();
}
i++;
}
在每次迭代的l
狀態:
[1,2,3,4,5,6,7,8] # i = 0, e = 1
[2,3,4,5,6,7,8] # i = 1, e = 2
[2,3,4,5,6,7,8] # i = 2, e = 3
[2,4,5,6,7,8] # i = 3, e = 4
[2,4,5,6,7,8] # i = 4, e = 5
[2,4,6,7,8] # i = 5, e = 6
[2,4,6,7,8] # i = 6, e = 7
[2,4,6,8] # i = 7, e = 8
[2,4,6,8] # i = 8, e = 2
[4,6,8] # i = 9, e = 4
[4,6,8] # i = 10, e = 6
[4,8] # i = 11, e = 8
[4,8] # i = 12, e = 4
[8] # i = 13, e = 8
[8] # i = 14, e = 8
[] # while loop exits
http://stackoverflow.com/questions/2622591/is -an-infinite-iterator-bad-design 這會回答你的問題。 – Nik 2012-03-06 06:07:13
啊,我不確定這裏的「無限迭代器」的解釋是什麼。如果你需要迭代一個開放式範圍,那麼@NikunjChauhan是正確的。如果你的意思是一個集合的無限迭代器,比如Google Collection庫,PHP和其他一些語言,那麼請看下面! – 2012-03-06 06:19:10