Format String as phone number in C#

Question

I have a string value 1233873600 in C# and I have to convert it to 123-387-7300 in C#

Is there any in-built function which will do that in c#?

possible duplicate of [How to format a string as a telephone number in C#](http://stackoverflow.com/questions/188510/how-to-format-a-string-as-a-telephone-number-in-c) — stuartd, Jan 20 '11 at 14:34

score 12 · Answer 1 · edited Jan 20 '11 at 14:35

12

Cast your string to a long and use the format "{0:### ### ####}";

string.Format("{0:(###) ###-####}", 1112223333);

edited Jan 20 '11 at 14:35

Joel Coehoorn

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answered Jan 20 '11 at 14:34

hunter

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score 3 · Answer 2 · answered Jan 20 '11 at 14:35

3

string phone = "1233873600".Insert(6, "-").Insert(3, "-");

answered Jan 20 '11 at 14:35

Greg

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score 3 · Answer 3 · answered Dec 05 '17 at 16:36

You can use a simple helper method that will take the string, sterilize the input in order to remove spaces or unwanted special characters being used as a separator, and then use the ToString method built-in. If you check for various lengths you can also assure the format comes out as you see fit. For example:

public string FormatPhoneNumber(string phoneNumber)
    {
        string originalValue = phoneNumber;

        phoneNumber= new System.Text.RegularExpressions.Regex(@"\D")
            .Replace(phoneNumber, string.Empty);

        value = value.TrimStart('1');

        if (phoneNumber.Length == 7)

            return Convert.ToInt64(value).ToString("###-####");
        if (phoneNumber.Length == 9)

            return Convert.ToInt64(originalValue).ToString("###-###-####");
        if (phoneNumber.Length == 10)

            return Convert.ToInt64(value).ToString("###-###-####");

        if (phoneNumber.Length > 10)
            return Convert.ToInt64(phoneNumber)
                .ToString("###-###-#### " + new String('#', (phoneNumber.Length - 10)));

        return phoneNumber;
    }

score 1 · Answer 4 · answered Jan 20 '11 at 14:36

1

I think regex is the best option.

this site is great for finding pre made regex strings.

http://www.regexlib.com/

answered Jan 20 '11 at 14:36

WraithNath

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score 0 · Accepted Answer · answered Jan 20 '11 at 14:34

0

You might want to use regex for this. The regex for North America phone number looks like this

^(\(?[0-9]{3}\)?)?\-?[0-9]{3}\-?[0-9]{4}$

I guess you can use Regex.Replace method in C#.

answered Jan 20 '11 at 14:34

Max Al Farakh

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using a format string would be the preferred method of doing this. both more readable and computationally faster. – cazlab Oct 24 '13 at 14:27

score 0 · Answer 6 · answered Oct 20 '20 at 12:54

0

String Format didn't work for me, so I did:

string nums = String.Join("", numbers);
return nums.Insert(0, "(").Insert(4, ")").Insert(5, " ").Insert(9, "-");

answered Oct 20 '20 at 12:54

Dragana

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Format String as phone number in C#

6 Answers6