How to do masking in C# ASP.NET

Hi Experts,

I want to mask an ID, inorder to hide the ID from the users, Like you know it should display only last 4 digits, all the other letters should be replaced with "X".

How can I achieve this, These are some of the sample ID's:


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Kamal KhaleefaInformation Security SpecialistCommented:
for each number take the count of each number
for example 520885659 is 9 characters
then take first 5 chracters and replace them with X

for example
this function
Right(520885659 , 4)
takes the last 4 digit of the number
Praveen VenuTechnical Project ManagerCommented:
try this
string data = "54-152-2360";
            int charsToShow = 4;
            string resultMasked= new string(char.Parse("*"),data.Length-charsToShow) + data.Substring(data.Length-charsToShow);

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dileepavAuthor Commented:
Hi Praveen,

It worked, but the users wanted to see the "-" or special characters as it is.

how can we achieve it? please help.

the string "54-152-2360" should be "XX-XXX-2360

Praveen VenuTechnical Project ManagerCommented:
try this
 string data = "54-152-2360";
            int charsToShow = 4;
            string maskedPart= System.Text.RegularExpressions.Regex.Replace(data.Substring(0,data.Length-4), "([0-9])", "*", System.Text.RegularExpressions.RegexOptions.Singleline | System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.IgnorePatternWhitespace);
            string resultMasked = maskedPart + data.Substring(data.Length - charsToShow);

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dileepavAuthor Commented:
Thx Experts.
It worked perfectly.

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