CODEWITHSUNDEEP
javascriptregex
tusar
tusar

Reputation: 3424

javascript regex validation issue

I am writing a javascript regex for the following:

  1. must have at least one digit
  2. must have at least one capital letter
  3. must be between 8-15 characters

I have tried it like this:

function isStrongPassword(strInput) {
    //works well except A1aaaaaa
    var regex = /^(?=.*\d)(^[A-Za-z0-9])(?=.*[A-Z]).{7,14}$/; 
    return regex.test(strInput);
}

This is working properly, except the fact it is not matching with A1aaaaaa, which is a valid input.

Any help is appreciated.

Upvotes: 0

Views: 109

Answers (2)

Billy Moon
Billy Moon

Reputation: 58619

Your regex was breaking because of the (^[A-Za-z0-9]) part, which would mean that after a digit, there must be a letter or digit, and then a capital letter. This should work

/^(?=.*\d)(?=.*[A-Z]).{8,15}$/;

Which breaks down like this...

/              
^              # start match
(?=.*\d)       # is there a digit up ahead (maybe after zero or more anythings)
(?=.*[A-Z])    # is there a capital up ahead (maybe after zero or more anythings)
.{8,15}        # 8 to 15 anythings
$              # end match
/

Upvotes: 1

Felix Kling
Felix Kling

Reputation: 817128

Your expression fails because of (?=.*[A-Z]). None of the characters following the first one is upper case.

It seems this expression should suffice:

^(?=[^\d]*\d)(?=[^A-Z]*[A-Z]).{8,15}$

Note that switching .* to [^...]* has nothing to do with your problem, but it avoids backtracking. Alternatively you could use lazy matching: .*?.

Upvotes: 1

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