javascript regex 需要至少一个字母，一个数字并防止添加某些单词

Question

I'm trying to modify my regex which requires user to type at least one letter and one digit which looks like this :

new RegExp('^(?=.*[a-z])(?=.*[0-9]).+$')

And I want to prevent user from using certain words like email address part before @ .

So let's assume the email address is example@example.com

I want to force user to use a string that doesn't contain example in it (any part of the string)

This is what I have so far:

\b(?:(?!example)\w)+\b

But it doesn't really force the user to use at least one character and one digit.

When I'm trying to restric it I'm ending up with this:

\b(?:(?!example).*[a-z].*[0-9])+\b

But now the strings must follow the order of example then a [az] and then [0-9]

Any help greatly appreciated

Thanks!

Answer 1

In your sample the negative lookahead disallows example only at start of the string. Just add .*? as joker to disallow the word anywhere in the string and use word boundaries \\b if needed.

/^(?!.*?example)(?=\D*\d)[^a-z]*[a-z].*$/i

• (?!.*?example) first lookahead disallows example anywhere in the line
• (?=\\D*\\d) second lookahead requires a digit after any amount of \\D non-digits.
• [^az]*[az] matches any amount of non -alphetic characters until an alphabetic.

See demo at regex101

Actually you just need two lookaheads for being independent of condition. One for the required digit and one for the word. The requirement of alphabetic can be done inside the pattern.

Lookarounds are zero-length assertions triggered at a certain position.