匹配字符串中的两个正则表达式

Question

I have this text "£24,250.00 (inc. VAT)"

I want a regex that will show ONLY "24250.00"

I've managed to get the last portion with:

( \(inc\. VAT\))

And separately I can get the £ and , with:

[£,]

But I can't seem to work out how to combine both expressions to just return what I want.

Note that the number is dynamic so will change depending on applicable costs on a website.

In theory I could just run it through two separate regex in my c# code each one trimming what I want. But is there a way that it can be done with just one expression?

Reason for this is I have a GetConvertedExtension method that takes an IWebElement, a string (the regex) and then converts the string to Double, Int etc

I don't really want to change this extension method or avoid using and going down the root of multiple expressions and then a parse statement.

I've used https://regexr.com/ to try getting a working solution but with no luck and starting to struggle.

I'm using Visual Studio 2017 and C# with the Regex library

Answer 1

If you want to use a single regex, you could use 2 capturing groups:

£(\d+),(\d+\.\d+) \(inc\. VAT\)

Then you could use group1 and group2 after each other to get your value.

If the decimal part after the dot can contain only 2 digits, replace the last \\d+ with \\d{2}

For example:

string pattern = @"£(\d+),(\d+\.\d+) \(inc\. VAT\)";
string input = @"£24,250.00 (inc. VAT)";

foreach (Match m in Regex.Matches(input, pattern))
{
    Console.WriteLine(m.Groups[1].Value + m.Groups[2].Value);
}

Result

24250.00

See a .NET regex demo | C# Demo

Answer 2

(?<currency>[£$€])(?<value>[0-9]{1,3}(?:,[0-9]{3})*\\.[0-9]{2})\\s\\(inc\\.\\sVAT\\)

I would use sometihng like this. I added the first capture group with currency just as I thought maybe this could be useful too? You'd just have to add which currency symbols you are interested in the square brackets.

In visual studio you:

var regex = new Regex(@"(?<currency>[£$€])(?<value>[0-9]{1,3}(?:,[0-9]{3})*\\.[0-9]{2})\\s\\(inc\\.\\sVAT\\)");

Then you do your regex.Match(data) or regex.Matches(data) or whatever you need to do.

Then to access the number in your match you need to access the value group so... match.Groups["value"].Value where match is what you've assigned to be your regex match.

Just to quickly run through the regex:

(?<currency>[£$€]) this is a named capture group which will capture £ or $ or € literally.

(?<value>[0-9]{1,3}(?:,[0-9]{3})*\\.[0-9]{2}) This is named capture group to get the number. Further breaking it down:

[0-9]{1,3} matches a digit from 0 to 9 between 1 and 3 (inclusive) times.
(?:,[0-9]{3})* matches the thousands seperated by commas 0 or more times.
\\.[0-9]{2} matches the decimal point and two digits after.

\\s\\(inc\\.\\sVAT\\) This matches literally the inc VAT bit after number. Using \\s instead of as whitespace because I find it easier to read.

NOTE: this regex only works for this number format with a comma for every thousand and always includes the decimal.