Doubt in Unboxing error

[learnjava1974]

Got a code from Complete Reference

class UnBoxingError
{
public static void main(String s[])
{
Integer iOb=1000;
int i=iOb.byte.value();
System.out.println(i);
}
}

The output is -24. I am not clear about how come we are getting -24? In the book it written that we are getting garbage value. But there should be some reason of getting this value -24.

[Fubarable]

1000 is greater than byte's maximum value of 127, and so you're getting an expected result.

[Norm]

For those who like bits and bytes:

    
     int ix = 1000;
     System.out.println("1000=" + Integer.toHexString(ix)); // 1000=3e8
     ix  = -24;
     System.out.println("-24=" + Integer.toHexString(ix)); //-24=ffffffe8

Notice the rightmost two nibbles(1 byte): e8

[Singing Boyo]

Think of it as if it wraps, and when a value goes over, it goes to the minimum value. 128 is greater than a bytes maximum value, so it 'wraps around' to -126. 1000 'wraps around' multiple times, and ends up at -24. It's not exactly what happens, and Norm's example is more complete, but it's an easy way to think of it when you're trying to figure out what happens when a numeric value goes over the maximum of its type.

[DarrylBurke]

Cross posted
OTN Discussion Forums : Doubt in Unboxing error ...

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