Code 1.~~~~~ using System;

class P { static void Main() { double d = 1.23456; Console.WriteLine(d); } } ~~~~~

Code 2.~~~~~ using System; class P { static void Main() { double d = 1.23456; Console.WriteLine(d); } } ~~~~~

Can you find difference between two?

Yes,It was JUST line feed. And,these two code lead to a different result.

Result 1.1,23456

Result 2.1.23456

It seems '.' replaced by ','.

The same problem occurs in Mono.

I think this probrem is bug,but I highly recommend to use substitute methods like this:

static string doubleToString(double d)
{
    int s = (int)d;
    string a = Convert.ToInt32((d - s) * 1000000000).ToString().PadLeft(9, '0');
    return $"{s}.{a}";
}

Proof: 33796322 33796340