CODEWITHSUNDEEP
c#regex
Slinky
Slinky

Reputation: 5832

C# RegEx for Numbers up to 100

I created a regex to match numbers from 1-100, including decimals such as 50.25

For some reason, decimal numbers are not matching and I have no idea why.

Can someone help?

string pattern = @"^([1-9][0-9]{0,1}(\\.[\\d]{1,2})?|100)$";
Regex r = new Regex(pattern);
Match m = r.Match(s.SearchRadius);
if (!m.Success)
{
    s.SearchRadius = "20";
}

Upvotes: 3

Views: 2442

Answers (4)

dav_i
dav_i

Reputation: 28137

Just to play devils advocate - the non-regex solution is:

double d;
if (!(double.TryParse(s.SearchRadius, out d) && d <= 100 && d >= 0))
{
    s.SearchRadius = "20";
}

And for good measure that famous quote by Jamie Zawinski:

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.

Upvotes: 2

Blaž Šnuderl
Blaž Šnuderl

Reputation: 378

Your code catches both the number xx.xx and .xx. If you want it to catch the number only once insert the ?: in the second parenthesis.

^([1-9][0-9]{0,1}(?:\.[\d]{1,2})?|100)$

Btw, a good way to test regular expressions is a site like http://rubular.com/ where u can see the results right away.

Upvotes: 0

Karmic Coder
Karmic Coder

Reputation: 17949

When using @"" string literals, you don't escape backslashes. You probably intended for \. and \d

@"^([1-9][0-9]{0,1}(\.[\d]{1,2})?|100)$";

Upvotes: 4

Mike Precup
Mike Precup

Reputation: 4218

You're using the @ sign on your string, so you shouldn't escape \ characters.

All you need is

string pattern = @"^([1-9][0-9]{0,1}(\.[\d]{1,2})?|100)$";

Upvotes: 9

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