Get the Opposite of a Regular Expression

Asked Jan 17 '19 at 04:38

Active Jan 17 '19 at 04:38

Viewed 58 times

I want to validate a form field, by preventing the user from entering the domain name with www or http so I wrote a regular expression as follows.

/^(www|http)/

What I want is the opposite of the written regular expression. So that I can have the expected result.

Expected result:

How to get the opposite of the regular expression

asked Jan 17 '19 at 04:38

Dulara Malindu

3

You need to use negative lookahead like this `/^(?!www|http).*/` [Demo](https://regex101.com/r/kqeic3/1) – Pushpesh Kumar Rajwanshi Jan 17 '19 at 04:39
3

you could write a regex that matches what you want then negate it in javascript `!regex.test(url)` – t3dodson Jan 17 '19 at 04:41
1

Thank you @PushpeshKumarRajwanshi You saved my day. – Dulara Malindu Jan 17 '19 at 04:49

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