redis添加数据不是加在原数据的后面？

Question

这是redis中原有的数据：

 1) "url:/doi/10.1002/anie.201601258/full"
 2) "url:/doi/10.1002/anie.201601883/full"
 3) "url:/doi/10.1002/anie.201600911/full"
 4) "url:/doi/10.1002/anie.201509978/full"
 5) "url:/doi/10.1002/anie.201601016/full"
 6) "url:/doi/10.1002/anie.201600841/full"
 7) "url:/doi/10.1002/anie.201511733/full"
 8) "url:/doi/10.1002/anie.201600918/full"
 9) "url:/doi/10.1002/anie.201601042/full"
10) "url:/doi/10.1002/anie.201601120/full"
11) "url:/doi/10.1002/anie.201602071/full"
12) "url:/doi/10.1002/anie.201509601/full"
13) "url:/doi/10.1002/anie.201511065/full"
14) "url:/doi/10.1002/anie.201601238/full"
15) "url:/doi/10.1002/anie.201510994/full"
16) "url:/doi/10.1002/anie.201601082/full"
17) "url:/doi/10.1002/anie.201509260/full"
18) "url:/doi/10.1002/anie.201601621/full"
19) "url:/doi/10.1002/anie.201510748/full"
20) "url:/doi/10.1002/anie.201601003/full"

Redis.set了三条数据，如下：

     1) "url:/doi/10.1002/anie.201601258/full"
 2) "url:/doi/10.1002/anie.201601883/full"
 3) "url:/doi/10.1002/anie.201600911/full"
 4) "url:http://www.peintopython.net/"
 5) "url:/doi/10.1002/anie.201509978/full"
 6) "url:http://www.brpreiss.com/books/opus7/html/book.html"
 7) "url:/doi/10.1002/anie.201601016/full"
 8) "url:/doi/10.1002/anie.201600841/full"
 9) "url:/doi/10.1002/anie.201511733/full"
10) "url:/doi/10.1002/anie.201600918/full"
11) "url:/doi/10.1002/anie.201601042/full"
12) "url:/doi/10.1002/anie.201601120/full"
13) "url:/doi/10.1002/anie.201602071/full"
14) "url:/doi/10.1002/anie.201509601/full"
15) "url:http://www.pearsonhighered.com/educator/academic/product/0,,0130260363,00%2Ben-USS_01DBC.html"
16) "url:/doi/10.1002/anie.201511065/full"
17) "url:/doi/10.1002/anie.201601238/full"
18) "url:/doi/10.1002/anie.201510994/full"
19) "url:/doi/10.1002/anie.201601082/full"
20) "url:/doi/10.1002/anie.201509260/full"
21) "url:/doi/10.1002/anie.201601621/full"
22) "url:/doi/10.1002/anie.201510748/full"
23) "url:/doi/10.1002/anie.201601003/full"

但是穿插在里面，为什么？
刚学redis，请教。

Answer 1

Set is unordered by definition. No matter how the program is saved, you should not believe that it can give you the original order. If you want order, use List.