How to add password validation using regular expression in angularjs according to certain criterion?

Question

I want to validate password entered by user for following criteria :

Password should be at least 8 characters long and should contain one number,one character an

Answer 1

As far as i understood your problem. Check your console It might be broken on lexical errors.

You forgot slash at start and at end of ng-pattern. Please use ng-pattern="/^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@$!%*#?&])[A-Za-z\d$@$!%*#?&]{8,}$/"

I have created a plunk which might help you. https://plnkr.co/edit/qCjp6a?p=preview

Answer 2

I took a stab at this with Angular's built-in pattern validator and was able to come up with the following that checks for:

• At least 8 characters in length
• Lowercase letters
• Uppercase letters

• Numbers Special characters

  password: [ '', [ Validators.required, Validators.pattern('(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[$@$!%*?&])[A-Za-z\d$@$!%*?&].{8,}') ] ]

I'll add that I'm by no means a regex expert. This is simply what worked for me for a closely related case to the OP. Maybe it will help someone else. Mozilla's documentation helped a lot in figuring this out, specifically the Writing a regular expression pattern section.

Answer 3

Just a couple notes

1) The above contains one redundant $. It should be ng-pattern="/^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/"

2) Don't remove leading ^ and trailing $ as it prevents from entering white spaces

3) If you want to define the pattern in controller then

$scope.passwordStrength = /^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/; and <input ng-pattern="passwordStrength">

but never

$scope.passwordStrength = "/^(?=.*[A-Za-z])(?=.*\d)(?=.*[@$!%*#?&])[A-Za-z\d@$!%*#?&]{8,}$/";

as the pattern is a RegExp object, not a string.

Hope this will help you save some time.

Answer 4

You can use this regex pattern it will work fine:

"/^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@$!%*#?&])[A-Za-z\d$@$!%*#?&]{8,}$/".

But you need to write it in .ts file (controller class) because if you write regex in .html file as the 'type' of the input field is a 'password' you will always throw the error "Invalid password". Because you are writing a regex to check the alphanumeric and special character input but as the input field is of type password then this regex will check the encrypted input which will always fail the case.