How to validate fields before onclick?

Question

AJAX

There is a form, it has 2 required fields (there is a required tag).
The data is sent on the onclick event of the button via ajax.
Is there any way to combine form validation with html and data transfer via ajax?
Naturally, there is to remove the processing of pressing the button with js, then the form is validated by html and everything is buzzing.

Answer 1

Yes, it all depends on what you need.
Do you want to check the form for valid/invalid characters?
On the number of these very characters?