Regular expression to remove certain characters after nth index value

[Lokesh]

We are working on a form validation code snippet where jQuery masking plugin has been used to enforce validation on user input.

Masking Pattern used with zip code field is 99999?-9999 where everything is optional after “?”.

Problem occurs when user fill up the form using autofill feature in chrome[i.e. double click on input field and select value] and submit the form. On form submission, zip code value is coming as 23455-____ which includes masking pattern characters as well i.e. hypen & underscore.

Refer attached screenshot after using autofill feature. http://inft.ly/3mmtNdA

If optional characters contains Hypen (-) and underscore(_) then those needs to be removed before submitting it to server. I am trying to use regex but didn’t find anything which checks for specific characters after 5th index item and then remove those.

Any help would be really appreciated.

[Paul_Wilkins]

You can use a global search for digits, which removes anything else that is not a digit.

'23455-____'.match(/\d/g) // ['2', '3', '4', '5', '5']

Or if you want the digits to be all joined together:

'23455-6789'.match(/\d/g).join(''); // '234556789'

[Lokesh]

@Paul_Wilkins Can’t use join as “-” is a must if zip code is filled with all 9 digits. Second, it is not always digits in zip code, there are few regions where zip code is alphanumeric. For ex. zip for canada is alphanumeric. So, i need to read masking pattern first to get the index of “?” then pass this index to regular expression to remove special characters after index value.

To overcome this combinations, i was searching for a regex pattern which returns string after 5th index value. For e.g. if string is “23345-_____” then that regex should search for “-” & “_” after 5th digit.

[Mittineague]

Do acceptable values always and only start with 5 digits?
If so you can specify like
[\d]{5}

Good regex is all about patterns, you need to recognize both what to include and what to exclude

[Lokesh]

Issue is resolved by simply strip the trailing underscores or dashes from the string like so:

var str = '12345-_____';
str.replace(/[-_]+$/, ''); // "12345"

var str = '12345-123__';
str.replace(/[-_]+$/, ''); // "12345-123"