How to hide the data on the user's confidential information page, leaving only the last few (numbers, letters)?

Question

css

There are fields with user data.
For example:
Phone number: (495) 333 33 33
And after saving the data (the same phone number) it should look like this:
Phone number: (495) *** ** 33
How can this be implemented in the front-end to prepare the back environment -enda?

Answer 1

And what's the point of doing it on the frontend while filling out the form? After all, you still have to store the whole number somewhere in the browser and anyone who wants to get it anyway. Of course, you can get confused with encryption, but this is too much already

Answer 2

You can't do it in the front-end, it must be implemented in the back-end.