Conversion from decimal to binary

DecimalToBinaryDemo.java

/**
 * Example: Conversion from decimal to binary
 * Reference: https://www.rapidtables.com/convert/number/decimal-to-binary.html
 * Sample Data:
 * 11 - 1011
 * 12 - 1100
 * 13 - 1101
 **/
public class DecimalToBinaryDemo {
    public static void main(String[] args) {
        int num=13, rem;
        StringBuilder ans= new StringBuilder();
        while(num>0){
            rem = num%2;
            num=num/2;
            ans.append(rem);
        }
        ans.reverse();
        System.out.println(ans);
    }
}