Thread: Making Binary Converter script from scratch, running into math issue.

I understand there are more simplified ways of doing what I am making now, but for the time being I am just using my current knowledge of Java to expand on what I already know. So right now I am making a script to convert between binary and text and vice versa. One issue I am having is that the decimal answer is coming out all wrong when I test the binary to text (decimal for now) part. I keep getting this 4-5 digit answer whenever I enter a 8-bit binary number. I've rechecked my code and broke it down to parts, printed each value through the loop but for some reason I get these bizarre numbers. Here's what I have, but keep in mind that THIS IS INCOMPLETE:

import java.lang.*;
import java.io.*;
import java.util.Scanner;
 
public class BinaryOrText
{
    public static void main(String[] args) throws IOException
    {
        int method;
        int iter = 0;
        int binary;
        int power = 0;
        int decimal;
        char binaryDigit = 0;
        String strBinary;
        String text = "";
 
        Scanner in = new Scanner(System.in);
 
        System.out.print("Pick a Conversion Method; Enter [1] to Binary | [2] to Text: ");
        method = in.nextInt();
 
        //text to binary
        if (method == 1){
            System.out.print("Enter text: ");
            text = in.next();
 
 
            char charT = text.charAt(0);
            System.out.println((int)charT);
            // ...Incomplete
        }
        //binary to text
        else if (method == 2){
            decimal = 0; //declare
            System.out.print("Enter Binary: "); //prompt
            binary = in.nextInt(); //assign original input
 
            strBinary = Integer.toString(binary); //make a string version
            power = strBinary.length() - 1; //sets the starting power by length of binary code
 
            for (int i = 0; i < strBinary.length(); i++){
 
                binaryDigit = strBinary.charAt(iter); //Takes binary digit from char position.
                decimal += binaryDigit*Math.pow(2,power); // digit * 2^pow.
                System.out.println(decimal);
                iter++; //Goes to next binary digit.
                power--; //Goes to power on next digit
 
            }
        }
    }
}

Can you show the program's input and output?
Add some comments to the output showing what you want it to be.

You did not show what the input you entered for the program.

Why do you read the input as int vs as String?

No I showed the input, here its in bold. I'm not sure if I know what you mean. I accepted it as an int because I needed to do some math with it. But then I made a String copy of it so that I can make an equation to determine the starting power by the length of it and to get chars from it. Then I used the power and binaryDigit variables to help bring the answer to the variable known as decimal.

I entered a 2 as I have bold-ed above for binary to text method. But I think I have figured out that, when I re-assign and add the chars from the binaryDigit variable, it translates it to its ASCII number first then assigns it. I figure this because I just made the equation, decimal += binaryDigit; and the first result in the output was 49, then it kept adding up to larger numbers until it hit 340. If this is the case, would you know how to make the decimal variable accept the char as is instead of taking its ASCII value?

You need to convert/parse the char value if you want to convert a '1' to a 1.
A quick and dirty way to do that is to subtract '0' from it.
'1' - '0' = 1

What you see is not what you get.
The problem with printing out '1' and 1 is that they print out the same. But your code was using the char in an formula that showed you that '1' was not 1. This is always a confusion for beginners.

You were quick to see it and now know about it and should not have trouble with it later.