using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\b6(?:011|5[0-9]{2})[ -]([0-9]{4}[ -]){2}([0-9]{4})\b|\b6(?:011|5[0-9]{2})(?:[0-9]{12})?$\b";
string input = @"Discover
Requirements: Discover cards start with the number 6011 or 65 and have 16 digits.
Pattern Parts:
Starts with number 6011 or 65, has 16 length, and has space or dash:
1) \b6(?:011|5[0-9]{2})[ -]([0-9]{4}[ -]){2}([0-9]{4})\b
Starts with number 6011 or 65, has 16 length, and has no space or dash:
2) \b6(?:011|5[0-9]{2})(?:[0-9]{12})?$\b
Combining 1-2 to form one pattern:
\b6(?:011|5[0-9]{2})[ -]([0-9]{4}[ -]){2}([0-9]{4})\b|\b6(?:011|5[0-9]{2})(?:[0-9]{12})?$\b
Test Cases:
Positive (Should fire):
16 length, no space, start with 6011 6011123412341234
16 length, dashes, start with 6011 6011-1234-1234-1234
16 length, spaces, start with 6011 6011 1234-1234-1234
16 length, no space, start with 65 6521123412341234
16 length, dashes, start with 65 6521-1234-1234-1234
16 length, spaces, start with 65 6521 1234 1234 1234
Embedded in sentence with space:
16 length, no space, start with 6011 Here is the cc: 6011123412341234
16 length, dashes, start with 6011 Here is the cc: 6011-1234-1234-1234
16 length, spaces, start with 6011 Here is the cc: 6011 1234-1234-1234
16 length, no space, start with 65 Here is the cc: 6521123412341234
16 length, dashes, start with 65 Here is the cc: 6521-1234-1234-1234
16 length, spaces, start with 65 Here is the cc: 6523 1234-1234-1234
16 length, no space, start with 6011 Credit Card#:6011123412341234
16 length, dashes, start with 6011 Credit Card#:6011-1234-1234-1234
16 length, spaces, start with 6011 Credit Card#:6011 1234-1234-1234
16 length, no space, start with 65 Credit Card#:6521123412341234
16 length, dashes, start with 65 Credit Card#:6521-1234-1234-1234
16 length, spaces, start with 65 Credit Card#:6523 1234-1234-1234
Negative (Should Not Fire):
16 length, no space, not start with 6012 6012123412341234
16 length, dashes, not start with 6012 6012-1234-1234-1234
16 length, spaces, not start with 6012 6012 1234 1234 1234
16 length, no space, not start with 66 6612123412341234
16 length, dashes, not start with 66 6612-1234-1234-1234
16 length, spaces, not start with 66 6612-1234-1234-1234
16 length, no space, start with 65, embedded Credit Card Number6521123412341234
16 length, dashes, start with 6011, malformed 601-11234-1234-1234
16 length num matching pattern but embedded User ID: 0000006011123412341234000000";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx