两个可能的字符数的正则表达式

Question

I need a regular expression for allowing two diferent character counts. I only want to allow a string whose length is either 5 or 7 characters but not any of the values in between.

For example: for 5 and 7

asdfg = ok
asdfgh = fail
asdfghj = ok

Thanks!

Answer 1

You can use this regex:

^.{5}(?:.{2})?$

RegEx Demo