Question

I have a string string rx;
and this string has the following type of data: “v=123.111i=10.123r=1234\r\n”

So, what I want:
-have a 3 floating point(or some other decimal var) variables, “v” i” and “r”.
-scan the string… with a format string like “v=%.3fi=%.3fr=%.3f\r\n” where %.3f is the value (3 decimal digits)

Answer 1

Use Regex and Double.Parse:

var inputString = @"v=123.111i=10.123r=1234\r\n";

foreach (Match match in Regex.Matches(inputString, @"\d+[.]?\d{3}"))
{
    double result = Double.Parse(match.Value);
}

explain:

\d+          digits (0-9) 
             (1 or more times, matching the most amount possible)

[.]?         character of: '.' 
             (optional, matching the most amount possible)

\d{3}        digits (0-9) 
             (3 times)

and I used Double.Parse. It converts the string representation of a number to its double-precision floating-point number equivalent.