loop-hw4

import java.util.Scanner;

public class hw4 {

    public static void main(String[] args) {
        int bin = 0, newNum = 0, temp = 0, flag = 0;

        Scanner s = new Scanner(System.in);

        System.out.println("Please enter a binary number:");
        bin = s.nextInt();// getting number from user
        temp = bin;// saving in temp for checking

        while (temp > 0) {// as long as the number bigger then 0 continue
            if (temp % 10 != 1 && temp % 10 != 0) {// checking if the number is not binary
                System.out.println("Not a binary number");// result if number is not binary
                temp = 0;// closing the while loop
                flag = 1;// flag for ending program
            }
            temp /= 10;// removing the rightist number
        }

        if (flag == 0) {// checking if flag is not ending program
            for (int i = 1; bin > 0; i *= 2) {// loop for power number and as long as the binary number is not 0
                newNum += (bin % 10) * i;// multiplying in the index, the index is the power number
                bin /= 10;// removing the rightist number
            }
            System.out.println("The decimal number is: " + newNum);// result
        }
    }

}