How to make a verification: mail or phone?

Question

PHP

Is it possible to do this so that it checks what the user entered: mail or phone. And all this in one input. And so that what he entered is saved in the browser as a login. If possible, how to implement it?

Answer 1

It seems to me that it is better to do validation on the Backend side (especially if you later save something in the database).
To do validation via jQuery, it will be convenient to use this plugin - https://jqueryvalidation.org/.
If without it then:
https://codepen.io/roman-sarwarow/pen/PoPzxoV