3.10.txt

《Microsoft Visual C# .NET 2003开发技巧大全》源代码

Listing 3.10 Using Regular Expressions to Replace Numbers in a Credit Card with xs
using System;
using System.Text.RegularExpressions;
namespace _12_RegExpReplace
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
Regex cardExp = new Regex( @”(\d{4})-(\d{4})-(\d{4})-(\d{4})” );
string safeOutputExp = “$1-xxxx-xxxx-$4”;
string cardNum;
Console.Write( “Please enter your credit card number: “ );
cardNum = Console.ReadLine();
while( cardExp.Match( cardNum ).Success == false )
{
Console.WriteLine( “Invalid card number. Try again.” );
Console.Write( “Please enter your credit card number: “ );
cardNum = Console.ReadLine();
}
Console.WriteLine( “Secure Output Result = {0}”,
cardExp.Replace( cardNum, safeOutputExp ));
}
}
}