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Validate float values with whitespace and punctation

Hi

I want to use regular expressions to validate my web application input. I'm new to regular expressions so excuse me for asking stupidly: I want to validate/match all float/double values like this:

3 500,00
500,50
5,55
3 400 500,00

As you can see I want to handle any number with whitespaces and two decimals. I guess someone takes this easily?

TIA

RightCoder

It's not clear what you want to do with the spaces. Here is an example that mixes Regex with Double.TryParse...

            string[] tests = {
                "3 500,00",
                "500,50",
                "5,55",
                "3 400 500,00",
                              };
            string pattern = @"(?<tryFloat>[\d,.]+)(\s*(?<tryFloat>[\d,.]+))*";
            Thread.CurrentThread.CurrentCulture = new CultureInfo("Fr-fr", true);
            foreach (string test in tests)
            {
                foreach (Match mx in Regex.Matches(test, pattern))
                {
                    foreach (Capture cx in mx.Groups["tryFloat"].Captures)
                    {
                        double dbl = 0.0;
                        if(Double.TryParse(cx.Value,out dbl))
                        {
                            Console.WriteLine("{0} is a valid floating point number",cx.Value);
                        }
                        else
                        {
                            Console.WriteLine("{0} is NOT a valid floating point number",cx.Value);
                        }
                    }
                }
            }

Les Potter, Xalnix Corporation, Yet Another C# Blog

Marked As Answer byRightCoder Friday, September 11, 2009 11:56 AM

xalnix

It's not clear what you want to do with the spaces. Here is an example that mixes Regex with Double.TryParse...

            string[] tests = {
                "3 500,00",
                "500,50",
                "5,55",
                "3 400 500,00",
                              };
            string pattern = @"(?<tryFloat>[\d,.]+)(\s*(?<tryFloat>[\d,.]+))*";
            Thread.CurrentThread.CurrentCulture = new CultureInfo("Fr-fr", true);
            foreach (string test in tests)
            {
                foreach (Match mx in Regex.Matches(test, pattern))
                {
                    foreach (Capture cx in mx.Groups["tryFloat"].Captures)
                    {
                        double dbl = 0.0;
                        if(Double.TryParse(cx.Value,out dbl))
                        {
                            Console.WriteLine("{0} is a valid floating point number",cx.Value);
                        }
                        else
                        {
                            Console.WriteLine("{0} is NOT a valid floating point number",cx.Value);
                        }
                    }
                }
            }

Les Potter, Xalnix Corporation, Yet Another C# Blog

Marked As Answer byRightCoder Friday, September 11, 2009 11:56 AM

xalnix

Hi Xalnix

Thanks for your answer and your code is running and works. All the test is Ok.

Great work!

RightCoder

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