Code of the blog "Deep dive into bits, bytes, shorts, ints, longs, signed, and unsigned with Java"

SignedUnsigned.java

// Read the full explanation of this code on this blog post:
// https://webtechie.be/post/2024-09-26-java-bits-bytes-short-int-long-signed-unsigned/
public class SignedUnsigned {
    public static void main(String[] args) {

        System.out.println("0 to 15 as bits:");
        System.out.println("Value\tBits\tHex");
        for (int i = 0; i <= 15; i++) {
            System.out.println(i
                    + "\t" + String.format("%4s", Integer.toBinaryString(i)).replace(' ', '0')
                    + "\t0x" + Integer.toHexString(i).toUpperCase());
        }

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("0 to 255 as bits:");
        System.out.println("Value\tBits\tHex");
        for (int i = 0; i <= 255; i++) {
            System.out.println(i
                    + "\t" + String.format("%8s", Integer.toBinaryString(i)).replace(' ', '0')
                    + "\t0x" + Integer.toHexString(i).toUpperCase());
        }

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Object min and max values");
        System.out.println(" ");

        System.out.println("Byte");
        System.out.println("    Min: " + Byte.MIN_VALUE
            + "\n\t= " + String.format("%8s", Integer.toBinaryString(Byte.MIN_VALUE & 0xFF)).replace(' ', '0'));
        System.out.println("    Max: " + Byte.MAX_VALUE
            + "\n\t= " + String.format("%8s", Integer.toBinaryString(Byte.MAX_VALUE & 0xFF)).replace(' ', '0'));

        System.out.println("Short");
        System.out.println("    Min: " + Short.MIN_VALUE
            + "\n\t= " + String.format("%16s", Integer.toBinaryString(Short.MIN_VALUE & 0xFFFF)).replace(' ', '0'));
        System.out.println("    Max: " + Short.MAX_VALUE
            + "\n\t= " + String.format("%16s", Integer.toBinaryString(Short.MAX_VALUE & 0xFFFF)).replace(' ', '0'));

        System.out.println("Integer");
        System.out.println("    Min: " + Integer.MIN_VALUE
            + "\n\t= " + String.format("%32s", Integer.toBinaryString(Integer.MIN_VALUE)).replace(' ', '0'));
        System.out.println("    Max: " + Integer.MAX_VALUE
            + "\n\t= " + String.format("%32s", Integer.toBinaryString(Integer.MAX_VALUE)).replace(' ', '0'));

        System.out.println("Long");
        System.out.println("    Min: " + Long.MIN_VALUE
            + "\n\t= " + String.format("%64s", Long.toBinaryString(Long.MIN_VALUE)).replace(' ', '0'));
        System.out.println("    Max: " + Long.MAX_VALUE
            + "\n\t= " + String.format("%64s", Long.toBinaryString(Long.MAX_VALUE)).replace(' ', '0'));

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Bits to byte");
        System.out.println("Byte value 00000001: " + ((byte) Integer.parseInt("00000001", 2)));
        System.out.println("Byte value 00001111: " + ((byte) Integer.parseInt("00001111", 2)));
        System.out.println("Byte value 01111111: " + ((byte) Integer.parseInt("01111111", 2)));
        System.out.println("Byte value 10000000: " + ((byte) Integer.parseInt("10000000", 2)));
        System.out.println("Byte value 10000001: " + ((byte) Integer.parseInt("10000001", 2)));
        System.out.println("Byte value 10001111: " + ((byte) Integer.parseInt("10001111", 2)));

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Byte to Integer with mask");
        var b = (byte) Integer.parseInt("10001111", 2);
        System.out.println("Byte value: " + b);
        var bWithMask = b & 0xff;
        System.out.println("Byte value with mask: " + bWithMask);
        System.out.println("Object Type: " + printObjectType(bWithMask));

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Byte to Integer with toUnsignedInt");
        var unsignedInt = Byte.toUnsignedInt(b);
        System.out.println("Byte to unsigned integer: " + unsignedInt);
        System.out.println("Object Type: " + printObjectType(unsignedInt));

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Byte to Long with toUnsignedLong");
        var unsignedLong = Byte.toUnsignedLong(b);
        System.out.println("Byte to unsigned long: " + unsignedLong);
        System.out.println("Object Type: " + printObjectType(unsignedLong));

        System.out.println(" ");
        System.out.println("------------------------------------");
        System.out.println(" ");

        System.out.println("Example with short");
        short s1 = (short) Integer.parseInt("1000000000000000", 2);
        System.out.println("Short value 1000000000000000: " + s1);
        System.out.println("Short value 1000000000000000 with mask: " + (s1 & 0xFFFF));
        System.out.println("Using Short.toUnsignedLong: " + Short.toUnsignedInt(s1));
        short s2 = (short) Integer.parseInt("1111111111111111", 2);
        System.out.println("Short value 1111111111111111: " + s2);
        System.out.println("Short value 1111111111111111 to unsigned: " + Short.toUnsignedInt(s2));
    }

    private static String printObjectType(Object obj) {
        if (obj != null) {
            return obj.getClass().getName();
        } else {
            return "NULL";
        }
    }
}