Convert a base 10 number to a base 3 number

Question

How to convert a base 10 number to a base 3 number with a method int converter(int num).

import java.util.Scanner;

public class BaseConverter {
    int answer;
    int cvt = 0;
    while (num >= 0) {
        int i = num / 3;
        int j = num % 3;
        String strj = Integer.toString(j);
        String strcvt = Integer.toString(cvt);
        strcvt = strj + strcvt;
        num = i;
        break;
    }
    answer = Integer.parseInt("strcvt");
    return answer;
}

public static void main(String[] agrs) {
    Scanner in = new Scanner(System.in);
    System.out.println("Enter a number: ");
    int number = in.nextInt();
    System.out.print(converter(number));
    in.close();
}

It was Compilation completed. But when I tried to run it, and entered a number, it showed that java.lang.NumberFormatException: For input string: "strcvt" I don't know how to fix it. How can I do this without using string?

Answer 1

"base 3 number" and "base 10 number" are the same number. In method int converter(int num) you're changing the number although you only need to change representation. Look at parseInt(String s, int radix) and toString(int i, int radix), that should help you.

Answer 2

You have to parse the value of strcvt not the string "strcvt"

So you have to remove the double qoutes answer = Integer.parseInt(strcvt); And define the variable strcvt outside the loop. change you code to:

public static int converter(int num) {
    int answer;
    int cvt = 0;
    String strcvt = null ;
    while (num >= 0) {
        int i = num / 3;
        int j = num % 3;
        String strj = Integer.toString(j);
        strcvt = Integer.toString(cvt);
        strcvt = strj + strcvt;
        num = i;
        break;
    }
    answer = Integer.parseInt(strcvt);
    return answer;
}