Thread: Underflow in Byte

Hello,

In the below code, we have underflow or overflow?
Byte in java is 1 byte. It means the capacity of a byte is 0-255.
400 - 256 (0 to 127 and -1 to -127). I expected we have 144. But we have -112 in output.
Could you please explain it?
Thanks

import java.lang.System;
import java.util.Scanner;
 
class test
{
 
 
    public static void main(String[] args) 
    {
        {
 
           byte b = (byte)400;
           System.out.println(b);
 
    }
}
}

Originally Posted by Norm

Use the Integer class's toHexString to see what the bits are for the value 400 = x190 or toBinaryString gives 1 1001 0000
The sign bit for the low order byte is 1 making it negative.
Casting it to a byte throws away the leading 1 leaving 1001 0000
Display the binary value of -112 gives 111111111111111111111111 1001 0000

Thank you for your answer, but I didn't understand well.
Could you please more explain about it?

The sign bit for the low order byte is 1 making it negative.
Casting it to a byte throws away the leading 1s leaving 1001 0000
Display the binary value of -112 gives 111111111111111111111111 1001 0000