Formatting a string into a phone number format

Printable View

Mar 1st, 2013, 03:46 PM
nbrege

Formatting a string into a phone number format

What's the easiest way to take a string like "9875551212" and reformat it into "(987) 555-1212"?
Mar 1st, 2013, 03:58 PM
dunfiddlin

Re: Formatting a string into a phone number format

Dunno about easiest but ...

Dim phone As String = String.Format("({0}) {1}-{2}", s.Substring(0, 3), s.Substring(3, 3), s.Substring(6))

Re: Formatting a string into a phone number format

vb.net Code:

String.Format("{0:(###) ###-####}", Long.Parse(inputString))

Might be handy in an extension method.

vb.net Code:

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim unformatted1 = "9875551212"
        '(987) 555-1212
        Dim formatted1 = unformatted1.ToFormattedPhone()
 
        Dim unformatted2 = "5551212"
        '555-1212
        Dim formatted2 = unformatted2.ToFormattedPhone()
 
        Dim unformatted3 = "123456"
        '123456 is an unknown phone number format
        Dim formatted3 = unformatted3.ToFormattedPhone()
    End Sub

vb.net Code:

Imports System.Runtime.CompilerServices
 
Public Module StringExtensions
    <Extension()>
    Public Function ToFormattedPhone(ByVal inputString As String) As String
        If inputString.Length = 7 Then
            Return String.Format("{0:###-####}", Long.Parse(inputString))
        ElseIf inputString.Length = 10 Then
            Return String.Format("{0:(###) ###-####}", Long.Parse(inputString))
        Else
            Return String.Format("{0} is an unknown phone number format", inputString)
        End If
    End Function
End Module

Mar 3rd, 2013, 10:12 AM
JuggaloBrotha

Re: Formatting a string into a phone number format

Quote:

Originally Posted by nbrege

What's the easiest way to take a string like "9875551212" and reformat it into "(987) 555-1212"?

How are you getting the unformatted number?
Is it coming from a database? Or directly from the user?
If it's coming from a database, are you the one getting from the user to put into the db?

It's always easier to get it from the user in a formatted way, I highly recomend using a MaskedTextBox where you can specify the literal characters in the number (like the parenthesis, the hyphen, & spaces) and let the user fill in the actual digits. You can make things like the area code optional within the MTB control too, using the correct Mask.
Mar 3rd, 2013, 07:53 PM
dunfiddlin

Re: Formatting a string into a phone number format

Quote:

I highly recomend using a MaskedTextBox

I suspect you're on your own on that one. It is a popular but entirely untrue myth that the masked textbox requires little or no validation! Foolproof, it ain't!
Mar 4th, 2013, 08:15 AM
nbrege

Re: Formatting a string into a phone number format

Quote:

Originally Posted by JuggaloBrotha

How are you getting the unformatted number?
Is it coming from a database? Or directly from the user?
If it's coming from a database, are you the one getting from the user to put into the db?

Yes, I'm retrieving from a database. It is being written by another program, which can't be changed...
Mar 5th, 2013, 10:39 AM
JuggaloBrotha

Re: Formatting a string into a phone number format

Quote:

Originally Posted by dunfiddlin

I suspect you're on your own on that one. It is a popular but entirely untrue myth that the masked textbox requires little or no validation! Foolproof, it ain't!

I never said anything about validation as validation will need to be done no matter what UI control you use, but what it does offer is a way to help the user enter the data into the desired format (using visual queues too) which would be much more ideal than a standard textbox in this case, that's the point I was getting across.

Quote:

Originally Posted by nbrege

Yes, I'm retrieving from a database. It is being written by another program, which can't be changed...

Then you'll want to consider making an extension method as MattP has suggested to keep the formatting in one place & have the flexibility for calling it from the string object directly.
Mar 5th, 2013, 11:50 AM
dunfiddlin

Re: Formatting a string into a phone number format

Quote:

but what it does offer is a way to help the user enter the data into the desired format

That would, could and possibly should be true but only if entry was restricted to a logical progression from left to right. The problem is less pronounced with the telephone mask although there are still multiple ways to muck it up but the date mask is a pain in the posterior that almost invites mistakes. As a user I find masked entries nothing but a nuisance that actually slows down data entry rather than 'helping'. I would not mourn their passing into history!
Mar 6th, 2013, 11:07 AM
JuggaloBrotha

Re: Formatting a string into a phone number format

Quote:

Originally Posted by dunfiddlin

That would, could and possibly should be true but only if entry was restricted to a logical progression from left to right. The problem is less pronounced with the telephone mask although there are still multiple ways to muck it up but the date mask is a pain in the posterior that almost invites mistakes. As a user I find masked entries nothing but a nuisance that actually slows down data entry rather than 'helping'. I would not mourn their passing into history!

You shouldn't be using a MaskedTextBox for date entries, you should be using the proper controls for the proper types of data, a MaskedTextBox is great for phone numbers, social security numbers, badge id numbers to name a few, for dates & times you should be using a DateTimePicker instead, or at the very least a Calendar control, never a MaskedTextBox.