Java double data type problem

[Rameshwar Soni]

Can anyone please explain me the output of the following program??? Thanks in advance

class No_System_Demo
{
	public static void main(String[] n) 
	{
		
		
		double d=020;			      // octal number 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 point so the same number 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

		
	}
}

[Jesper de Jong]

The notation for octal number literals, starting with 0, is only for integers.

020 is an integer literal, so it is interpreted as an integer with the decimal value 16, which you then assign to a double, so that the int gets converted to a double.

020.0 is not an octal floating-point literal. It's a decimal floating-point literal; that's why you see the value 20.0 (decimal) printed. A leading 0 when writing a floating-point literal does not mean that the notation is octal.

Look at section 3.10.1 and 3.10.2 of the Java Language Specification for the exact details.