Simple phone number formatting question

[JabbaTheNut]

I have phone numbers that are in 10 digit format (i.e., 2125558888). I want to format them in the following manner: "(212) 555-8888".

I know I can do the following:
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string myNum = "2125558888"; //the source would be a field in a database

string myPhone;

myPhone = "(" + myNum.Substring(0,3) + &quot " + myNum.Substring(3,3) + "-" + myNum.Substring(6,4);

--------------------------------------------

However, I would like to do something more concise like this:
--------------------------------------------

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

--------------------------------------------


What is the proper syntax to do this?

Game Over, Man!

 

[obislavu]

Solution 1:

string myNum = "2125558888"; 
string sPhoneFormat1 = "({0:000}) {1:000}-{2:0000}";
string myPhone = string.Format(sPhoneFormat1,myNum.Substring(0,3), myNum.Substring(3,3),myNum.Substring(6,4));
Here you can have different format like
sPhoneFormat2 = "1-({0:000})-{1:000}-{2:0000}";
Of course you should ckeck the length of the myNum or put above in atry-catch block.

Solution 2:
Using regular expression:
string myNum = "2125558888"; 
string sPhoneFormat1 = "({0:000}) {1:000}-{2:0000}";

string sPhonePattern =  @"(\d{3})(\d{3})(\d{4})";
Match m= null;
m=Regex.Match(myNum,sPhonePattern);
if (m.Success )
{
	myPhone = string.Format(sPhoneFormat1, m.Result("$1"),m.Result("$2"), m.Result("$3"));
}
else 
{
// Wrong Phone number 
}

Solution 3:
Write your PhoneFormat Attribute class to format phone numbers:
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public class PhoneFormatAttribute : Attribute
{
	internal string strPattern;     
	internal string strOutputFormat;
public PhoneFormatAttribute (string sPattern, string sOutputFormat)
		{
		strPattern     = sPattern;
		strOutputFormat= sOutputFormat;
		}
public string PhoneFormat(string strPhone)
		{
                  // Use regular expression to format strPhone string depending on the strPattern and strOutputFormat
                  // return formatted string or null
                }
}

How to use this attribute at a level class ?


[PhoneFormat(@"(\d{3})(\d{3})(\d{4})", "({0:000}) {1:000}-{2:0000}")] 
		 )]
public class MyClass
{

public virtual string TransformPhone(string strPhone)
{
	try
	{
		Type type = this.GetType();
		PhoneFormatAttribute [] AttributeArray = PhoneFormatAttribute []) type.GetCustomAttributes(typeof(PhoneFormatAttribute ), false);
	if( AttributeArray.Length == 0 )
	{
	// Phone PhoneFormatAttribute object undefined for this class or it is called from a derived class but the inherit property is false
        	return  null;	
	}
	// Retrieve the one and only instance of PhoneFormatAttribute from this class
		return AttributeArray[0].PhoneFormat(strPhone);
	}
	catch (Exception e)
	{
		string sMsg= e.GetType().Name + ":" + e.Message;
		throw new Exception(sMsg);
	}
}
}

MyClass c1 = new MyClass();
string strPhone = c1.TransformPhone("2125558888");

-obislavu-