用PHP编号REGEXP

Question

I try to accept file names from 01.jpg to 12.jpg with this regexp :

preg_match('/^([0-1][0-2]\.jpe?g)$/i', $_FILES['Filedata']['name'])

01.jpg, 10.jpg, 11.jpg, 12.jpg are OK

but not 02.jpg to 09.jpg !!!

Thanks for your help !

Answer 1

尝试这个

 '/^(0[1-9]|1[0-2])\.jpe?g$/i'

Answer 2

You need:

^(0[1-9]|1[012])\.jpe?g$

0[1-9] takes care of 01 , 02 and so on till 09

1[012] which is same as 1[0-2] takes care of 10 , 11 and 12

Note the use of () carefully. Since | has the least precedence in regex operators:

^(0[1-9]|1[0-2]\.jpe?g)$ 

(from the other upvoted answer) is incorrect as it is treated as:

^(0[1-9] 

OR

1[0-2]\.jpe?g)$ 

See it