May 3, 2020
Depending on the business or even the form, you may be asking for certain information that always has a specific formatting.
Phone numbers are ten numbers long, email addresses have the structure ‘xx@xx.xx’, etc.
It’s helpful if the form checks whether this is correct once it’s filled out. If not, then it can give an error message so the user knows to correct something.
This can prevent painful mistakes like a phone number consisting of nine characters. Trust me, I’ve made the mistake before, and an extra pair of eyes to double-check things can’t hurt.