Extracting Numbers from String RegEx

Question

I am really struggling with Regular Expressions and can't seem to extract the number from this string

"id":143331539043251,

I've tried with this ... but I'm getting compilation errors

var regex = new Regex(@""id:"\d+,");

Note that the full string contains other numbers I don't want. I want numbers between id: and the ending ,

Answer 1

Try this code:

var match = Regex.Match(input, @"\""id\"":(?<num>\d+)");
var yourNumber = match.Groups["num"].Value;

Then use extracted number yourNumber as a string or parse it to number type.

Answer 2

If all you need is the digits, just match on that:

[0-9]+

Note that I am not using \d as that would match on any digit (such as Arabic numerals) in the .NET regex engine.

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Update, following comments on the question and on this answer - the following regex will match the pattern and place the matched numbers in a capturing group:

@"""id"":([0-9]+),"

Used as:

Regex.Match(@"""id"":143331539043251,", @"""id"":([0-9]+),").Groups[1].Value

Which returns 143331539043251.