Learning to Program

A Pattern for Phone Numbers

At this point, you have learned enough to get started on the project of validating phone numbers. First, we need to think of the different valid phone number formats. Here are a few possibilities:

1-555-867-5309

555-867-5309

[phone]

We can quickly experiment with these three formats using an online regular expression tool called regexpal: http://regexpal.com/. In the upper box, we enter our regular expression (no ...