ByteManager.java

package cryptography;

//Convenience class to:
//* break a byte into nibbles
//* merge the nibbles to reform the byte

class ByteManager 
{
    //static method:
    //* accessible without object
    //* all inputs are as parameters and outputs as return
    //* doesnt update the data members of the class
    //* can update the static data members of the class
    //* cannot directly access the non static methods
    
    static int[] byteToNibble(int x)
    {//‭104‬ ---> ‭[0110,1000‬]
        int arr[] = new int[2];
        arr[0] = (x & 255) >> 4;//higher nibble
        arr[1] = x & 15;//lower nibble
        return arr;
    }
    
    static int nibblesToByte(int nibbles[])
    {//‭[0110,1000‬] ---> 104
        return ((nibbles[0]&15)<<4)| (nibbles[1]&15);
    }
}