如何修改正则表达式以限制字符数最少 8 到最多 20

Question

I have the following regular expression. Now I want to modify it to restrict characters count from 8 to 20.

Minimum characters count should be 8 and maximum 20

^(\+\d{1,2}\s?)?1?\-?\.?\s?\(?\d{2,6}\)?[\s.-]?\d{3,6}[\s.-]?\d{1,4}$

The current expression accepting the following strings but it shouldn't in my case. The string count should be always greater than 8

123456
1234567

Here are more test cases:

https://regex101.com/r/hDNCkT/1

Answer 1

You can use a positive lookahead to limit the overall length of your match. After the carat, insert (?=.{8,20}$) . However, if you need to ensure there are 8-20 digits , you could use (?=(\D*\d){8,20}$) instead.

Example