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c#regexstring-parsing

Extract double number value with exponent from text

How could I extract a number of type double which may have exponent from a string with more character?

For example extract 56.8671311035e-06 from

"this is a string with a number inside 56.8671311035e-06 and the string continues here"

I guess it could be done using regular expressions, but my knowledge of them is very limited.

Solution

  • Yep, I'd say regular expressions are your friend here:

    var match = Regex.Match(input, @"[0-9.]+e[-+][0-9]+");

    Or you can prevent matching multiple decimal points with the following (the last one will be treated as the "proper" one):

    @"\b[0-9]+(.[0-9]+)e[-+][0-9]+\b"

    Edit: Here's a more complete one that will allow optional exponents and will also allow for the decimal point to be at the start of the number:

    @"[\d]*\.?[\d]+(e[-+][\d]+)?"