How to validate for a empty field for a mobile no in flutter?

Question

How do I validate for a empty phone number field in a form in flutter without using any extra packages or dependencies?

Answer 1

The easiest way is to check the conditions before printing/returning the values. Check for the following conditions before printing/returning the values. Pass the following conditions in the onPressed.

    if(value == null || value.length <10)
      print('Enter valid input');
    else
      print(value);