ref in and Out in dot net

class Test
{
	void refDemo(ref int i)
	 {
		i= i*10;
	 }
        int FindDecimal(float f,out float dp)
	 {
		int i=(int) f;
                dp=f-i;
                return i;
	 }
}

class RefExample
{
  public statc void Main(string []args)
   {
	Test obj=new Test();
        int i=10;
	Console.WriteLine("Before Call i:" + i);
	obj.refDemo(ref i);
	Console.WriteLine("After Call i:" + i);
	obj.FindDecimal(12.2345f,out float f);
	Console.WriteLine("Decimal points f:" + f);
   }
}