jQuery RegEx. If string contains any character except

Question

I've got this RegEx which is used to validate what the user enters

It must be a value 8 - 16 characters long and can contain ONE of the certain special characters.

/^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[:;#~]).{8,16}$"

I'm not trying to show an alert if the user enters something that doesn't match the above. So a-z, A-Z, 0-9 and :;#~ are allowed but anything else shows an alert.

So Abcd1234# is OK, but if they enter Abcd1234!$ if will show the alert as ! & $ are not in the match.

I've tried adding ^ to the start of character match to try and negate them, but that didn't work.

What's the best way to do this?

You mean you want to only allow the chars mentioned in the lookaheads? /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[:;#~])[\da-zA-Z:;#~]{8,16}$/? — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Jul 11, 2017 at 9:55
can contain or must contain ??? your regex ensures it must have A-Z but you said abcd1234# is ok — Mustofa Rizwan
– Mustofa Rizwan, Commented Jul 11, 2017 at 9:58
Why should abcd1234# match if you require an uppercase ASCII letter? It should not match. — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Jul 11, 2017 at 10:01
the input needs to be 8-16 characters long, MUST contain lower AND upper case letters, digits and any of the special characters. Anything else should show the alert. — Tom
– Tom, Commented Jul 11, 2017 at 10:01

Wiktor Stribiżew · Accepted Answer · 2017-07-11 10:27:15Z

2

It seems you only need to allow the characters mentioned in the lookaheads, create a character class with them and replace the last . with it:

/^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[:;#~])[\da-zA-Z:;#~]{8,16}$/
                                            ^^^^^^^^^^^^^^

See the regex demo

The [\da-zA-Z:;#~]{8,16} pattern will match 8 to 16 chars that are either digits, ASCII letters, or :, ;, # or ~ symbols.

Details:

^ - start of string
(?=.*\d) - there must be a digit after any 0+ chars other than line break chars (a (?=\D*\d) will be more efficient as it is based on the contrast principle)
(?=.*[a-z]) - - there must be an ASCII lowercase letter after any 0+ chars other than line break chars (a (?=[^a-z]*[a-z]) will be more efficient)
(?=.*[A-Z]) - there must be an ASCII uppercase letter after any 0+ chars other than line break chars (a (?=[^A-Z]*[A-Z]) will be more efficient)
(?=.*[:;#~]) - there must be a :, ;, # or ~ after any 0+ chars other than line break chars (you may also use (?=[^:;#~]*[:;#~]))
[\da-zA-Z:;#~]{8,16} - 8 to 16 chars defined in the character class
$ - end of string.

edited Jul 11, 2017 at 10:27

answered Jul 11, 2017 at 10:03

Wiktor Stribiżew

631k41 gold badges502 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Tom Over a year ago

Thanks this seems to do what I need. is there a site which will break this down and explain what it all means ?

Tom Over a year ago

Sorry missed that. Thanks

Collectives™ on Stack Overflow

jQuery RegEx. If string contains any character except

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related