Java double data type problem

[Rameshwar Soni]

can anyone explain me the output of the following program :
Thanks in advance

// program

class No_System_Demo
{
  public static void main(String[] n) 
  {
    double d=020;	// octal no 20 stored
    System.out.println("d=" +d);    // output will be in decimal number system and is 16.0 and thats fine
		
    
   double d1=020.0;   // octal no's can have a decimal so     the same no 20 or say 20.0 is stored
   System.out.println("d1=" +d1);  // but this time why the output isn't in decimal number system, it displays 20.0 instead of 16.0
		
   }
}