Java Program that converts numbers to binary using strings concatenation some how.

[lemony7]

 * 
 */
import java.util.Scanner;

public class Bits {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		String binary;
		while (n > 0) {
			binary = "" + n % 2;
			n = n / 2;
			System.out.print(binary);
		}
	}
}

/**

This is what I have so far. I understand there is an easier way of converting numbers into strings using a stringbuilder but my professor wants me to use string concatenation to get a binary output.

The instruction says to use a string to accumulate the results which I believe I did and to use string concatenation for each digit instead of integer addition. I tried using substring to reverse the order or even charAt so I can at least reverse the order and concatenate it myself but my java compiler won't let me do that and says it is out of range or something when i tried substring and charAt.

So I have no idea how to reverse my output so It can be properly in binary using string concatenation only. Please help.

[Eranga]

Actually the way you concatenate is not correct.

        String binary = "";
        int val = 0;
        while (n > 0) {
        	val = (n % 2);
        	n = n / 2;

            binary = (val) + binary;
        }
        System.out.print(binary);

[Eranga]

Apart from that you can do this with toBinaryString(). Read wrapper Integer to find out more.

[Eranga]

Please find the link below.

Java 2 Platform SE v1.3.1: Class Integer

And also if you think it is worth to have a look at the exception you end up with in charAt() something post it here. We can discuss.

[DarrylBurke]

Um, not Java 1.3!

Java Platform SE 6
Java Platform SE 7

db

[Eranga]

Oh yes db. I pick the wrong library from my collection. Thanks for the update.