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I don't understand the meaning of the following codes. Could anyone tell me? Thank you very much!
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int commaPos = input.IndexOf(',');
            double param1 = Convert.ToDouble(input.Substring(0, commaPos));
            double param2 = Convert.ToDouble(input.Substring(commaPos + 1, input.Length - commaPos - 1));
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SubString is kinda like the old VB's mid function

So the 2nd line gets the letters from the start to commapos, which the first line sets to the position of the first comma.
The 3rd line gets the letters from commpos+1 to the end of the string, which is worked out by taking the full lenght of the string-your start position.

Hopefully that makes enough sense:) Too early for me

Thank you very much! According to your statement, I found the reason about why I can't understand.
I think I make a mistake.

I'm also straggled with this code.thanks God I found answer from here.
Now I understand from ur explanation.
Thank u:)
(0,commaPos)means from start to that comma code.
(commaPos+1,input.Lenth-commaPos-1)means this is start from the end of that comma to the end of the code."+1"because give a space to comma,right?