JS正则表达式-允许使用双连字符

Question

I have the below regex to do some validation for user input.

^\s{0}$|^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?)*\.?$

The user input will be in the format myInvoices--2015Jan12--04-10-11

However, the regex above only allows names with 1 hyphen/dash: myInvoices-2015Jan12-04-10-11 rather than double dashes.

Can someone tell me how can I allow the user to input double dashes as well?

Thanks

Answer 1

^\s{0}$|^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-{1,2}){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-{1,2}){0,61}[0-9A-Za-z])?)*\.?$

我为您添加了{1,2} -允许一两个破折号

Answer 2

You should just need to add -? , ie an optional hyphen, after each current hyphen. So \\b- becomes \\b--? :

^\s{0}$|^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b--?){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b--?){0,61}[0-9A-Za-z])?)*\.?$

This matches your sample input