Question

I’m trying to understanding this code, which is about generating a Huffman tree. What is the use of this method in this code? Please explain it clearly. Thanks

public static Byte toByte(String str) {
    int io = 0;
    for (int i = 0; i < str.length(); i++) {
        io += Math.pow(2, i) * Byte.parseByte(str.charAt(str.length() - i - 1) + "");
    }
    return (byte) io;
}

Answer 1

Looking quickly at the code, it would appear that the method is used to convert a String of bits representing a byte to an actual byte. For example, it would translate “1101” to a byte value 0x0D.

It does this by analysing each individual character in the string, starting at the least significant character (ie: str.charAt(str.length()-1 -i) ), converting it to a byte (value in theory should be 0 or 1), and then multiplying it by a power of 2 depending on its location in the string (ie: Math.pow(2,i)), where the least significant position has a factor of 0.

It sums up all the “bits” and gives you a final answer.

Not – that there seems to be no error checking on the individual bits that it is parsing in the string, but there should only be 0 and 1 represented in the string.