正则表达式 - 匹配某个字符串并获取字符串的整数值

Question

I have a regex:

var example= Regex.Match(result, @"\b(Today is:)[\s:]*(.*)", RegexOptions.IgnoreCase);

and then I convert

example= int.Parse(result.Groups[2].Value, System.Globalization.NumberStyles.AllowThousands);

This works fine most of the time, however, I noticed that if I have extra string after Today is: for example,

Today is (extra):

My regex above fails for this case, because it also grabs "(extra)" and then goes to int.Parse, it fails. I want my regex to match when there's "Today is:", then it doesn't matter even if there are more strings, just get the string and convert into int value.

For example, Today is: 100,000,000 -> convert and get int 100000000

Today is (abc123): 88,888 -> convert and get int 88888

Today is (Extra Text blah blah): 100,000 -> convert and get int 100000

Answer 1

I would change a bit your regex like this:

\bToday is\b.*?\s*:\s*([\d,\.]+)

Test it here: https://regex101.com/r/jPb6Pa/1

Explanation:

• \\bToday is\\b for searching " Today is " and not " Blablatoday isn't " or something like that.

• .*? searches anything after " Today is " but in an ungready way.

• \\s*:\\s* searches for the ":" char with or without spaces around.

• The capturing group n°1 ([\\d,\\.]+) will search for digits, points and commas, at least one character. It could be improved as a single comma or point would be wrong. But it does the job for the moment.

Answer 2

You can use

\bToday\s+is\b(?:.*?\([^()]*\))?.*?\b(\d+(?:,\d{3})*(?:\.\d+)?)

See the regex demo . Parse the match.Groups[1].Value .

Details :

• \\bToday\\s+is\\b - Today is as whole words with any one or more whitespaces in between
• (?:.*?\\([^()]*\\))? - an optional sequence of any zero or more chars other than newline char as few as possible followed with a ( , zero or more chars other than ( and ) and then a ) char
• .*? - any zero or more chars other than newline char as few as possible
• \\b - a word boundary
• (\\d+(?:,\\d{3})*(?:\\.\\d+)?) - Group 1: a number pattern.