validating string variable in c#

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Hi

I have a string variable as below.

string referenceNumber;
i want to validate referenceNumber as it should contain only alphabets,numbers and underscore(_).
ex:- ghk234_1

it should not allow any other except alphabets,numeric,and underscore(_).
Regards,
Nagaraju

Posted 24-Mar-11 4:52am

nm.nagaraju

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Toli Cuturicu 24-Mar-11 16:25pm

Are you sure you allow it to start with a digit?
Isn't it supposed to be a programming language identifier?

2 solutions

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Manfred Rudolf Bihy · Accepted Answer · 2011-03-24T04:59:00

Solution 2

Look into regular expressions: System.Text.RegularExpressions.Regex.

String testString = "ghk234_1";
String regExpString = "[a-zA-Z0-9_]*";
Regex regex = new Regex(regExpString);
Match match = regex.Match(testString);
if(match.Success)
{
    //String was OK
}
else
{
    //String was not OK
}

Best Regards,

Posted 24-Mar-11 4:59am

Manfred Rudolf Bihy

Comments

Nuri Ismail 24-Mar-11 12:04pm

Good answer, my 5.

BTW: Using "\w" instead of "[a-zA-Z0-9_]" is shorter but maybe the longer version will be much clear for the OP. :)

Best Regards,
Nuri

Manfred Rudolf Bihy 25-Mar-11 5:45am

Thanks Nuri!

Sergey Alexandrovich Kryukov 24-Mar-11 14:45pm

Correct, a 5.
--SA

Manfred Rudolf Bihy 25-Mar-11 5:45am

Thanks SA!

Pavel Yermalovich · Accepted Answer · 2011-03-24T04:57:00

Solution 1

Use regular expressions. It's the most efficient way to analyze text information.

Posted 24-Mar-11 4:57am

Pavel Yermalovich

Comments

Sergey Alexandrovich Kryukov 24-Mar-11 14:46pm

Short... why not? My 5.
--SA