Out put of program

[Punya Pratap Singh]

Hi,
why is out put is coming -126,instead of 127 please clearly Expalin .I guess that there is some sign bit effect but don't understand what is it please help me.

Thanks

class Casting {
public static void main(String [] args) {
long l = 130L;
byte b = (byte)l;
System.out.println("The byte is " + b);
}
}

[Matt Cartwright]

you're right, the byte primitive in Java is signed (data types).

internally (at byte code level) the JVM converts 'byte' and 'short' primitives to type 'int'.
The effect we are seeing here is called "(integer) overflow" and leads to a model of so-called "circular arithmetic",
in which the greatest positive integer is followed by the smallest negative integer.

Why not change the representation to hexadecimal?

class Casting
{

   public static void main( String[] args )
   {
      long l = 130L;
      byte b = (byte) l;

      System.out.println("The long is " + String.format("0x%X", l));
      System.out.println("The byte is " + String.format("0x%X", b));
   }
}

HTH
Matt

[Wim Vanni]

Related Ranch Question (RRQ)

Cheers,
Wim

[Punya Pratap Singh]

Thanks a lot Matt Cartwright,but why to print in hexadecimal ?
Thanks Wim.

[Matt Cartwright]

short answer: because it's a byte and not a decimal number, the bits set do count, not its representation in decimal notation