Validating addresses with google
At the time of designing the form, expand the “Data Validation” section below the form field (see screenshot above) and choose Regular Expression from the drop-down.
And even if the format is proper, is the data itself valid?
Google Forms makes it relatively easy to add such advanced date validation rules to individual fields through Regular Expressions (or regex or regexp).
Think of them as search patterns and every character entered in a form field is matched against that pattern – the form can only be submitted if the patter and the user-input matches. Say your Google form expects the user to enter their year of birth.
The field will now accept input value like 1920, 2010 but would reject other values that fall outside the range.
A regular expression may appear gibberish but they aren’t so difficult to read and understand if you can know the basic rules of the language.