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Regular Expression for numbers

My problem seems simple but the solution has evaded me so far. I want to validate that a number is in a set of possible numbers.

For example:
value = 22
possible values = (11,22,33,44)

Can anyone provide a regular expression that will validate 22 but not 2 or 222? Does that make sense?

ozymandias

(11|22|33|44) ?

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Expert1701

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SOLUTION

ozymandias

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ozymandias

Expert1701 :

Regex.Match("2", "^(11)|(22)|(33)|(44)$").Success; <-- returns false
Regex.Match("22", "^(11)|(22)|(33)|(44)$").Success; <-- returns true
Regex.Match("2222", "^(11)|(22)|(33)|(44)$").Success; <-- returns true
Regex.Match("12344", "^(11)|(22)|(33)|(44)$").Success; <-- returns true

Fernando Soto

Hi CBeach1980;

Here is some sample code to do what you want.

using System.Text.RegularExpressions;

private void button2_Click(object sender, EventArgs e)
{
string possiblevalues = "11,22,33,44";
MessageBox.Show(ValidateNumber(possiblevalues, textBox1.Text).ToString());
}

private Boolean ValidateNumber(string findin, string num)
{
num = num.Trim();
try
{
int digits = Convert.ToInt32(num);
}
catch
{
return false;
}

return Regex.IsMatch(findin, @",?\s*(" + num + @")\s*,?");
}

Fernando

ozymandias

You would need and extra group : "^((11)|(22)|(33)|(44))$" to make it work.

CBeach1980

ASKER

Thank you both. They both are good answers though ozymandias' is a little cleaner.

Expert1701

Whoops, thank you for the correction, ozymandias!