Type for phone number?

[Campbell Ritchie]

You pass 01234567890 to the constructor and it works out how much of that is dialling code and how much local number. You pass Locale.USA, 2345678910 to the factory method and it parses the phone number into [phone] and finds the UsaPhoneNumber subclass and returns an instance of it.

[Campbell Ritchie]

...And how do mobile numbers differ from landline numbers in USA?

[Prasanna Raman]

Ok, and what if the formatting also differs by the type - mobile or landline? USA may be the same, but assuming it's different.

[Campbell Ritchie]

Write down what the format is, something like this:-

(0 two digits)space four digits space four digits

Similarly for all the formats you are actually going to use.
Work out how to get from this:-

[phone]

to

01234567890

I thikn you can do it very simply by putting the text into a StringBuilder and stripping all the non‑digit characters. You mighr wish to throw an exception if you remove anything other than punctuation and spaces. But this is your app; you will have to decide.

[Knute Snortum]

Campbell Ritchie wrote:...And how do mobile numbers differ from landline numbers in USA?

I don't think there's any difference.

[Junilu Lacar]

There is no difference between mobile and land line phone numbers in the US as far as I know. All of the numbers I've ever seen have a three-digit area code and a seven-digit phone number.

[Prasanna Raman]

Correct, there is no difference, but I'm just trying to program for any country thay may have different formats! And see how I can make it work.

[Campbell Ritchie]

Try UK; we have dialling codes with 3 4 5 or 6 digits, but all phone numbers start 0 and have ten more digits.