Regular expression in java for validating numbers
escaping - by -) [0-9] : It matches digital number from 0-9. That means, you could be very sure about the form, whether users have entered the details or not.There may be different requirements to validate username.This example covers most common requirement of them. Here is the initial pattern as per the requirements.These usernames are valid as per our defined requirements but in real world they might not.
In short, underscore (_) and (.) cannot appear in sequence.
Validation codes will return an alert message, if it finds some empty fields in the form.
Regular expression in java for validating numbers comments