使用javascript验证输入的顶级域

Question

How can I validate a domain name from a url input? I'm currently validating to www.domain.com , but need to be able to validate to just domain.com . So if a user enters www or http://www. , it needs to show the error. Also need to disable the content section from showing, unless the validation passes, instead of showing only if the input is not blank.

Currently using:

var regExp = new RegExp("^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-     
9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$", "g");

but this is validating to www.domain.com

jsFiddle: Link

Answer 1

^(?!www\\.|http:\\/\\/www\\.)(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]*[a-zA-Z0-9])\\.)+([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\\-]*[A-Za-z0-9])$

Simply add negative lookahead .See demo.

https://regex101.com/r/tS1hW2/7