RECURSION - Java Programming: From Problem Analysis to Program Design - page 891

prints 1 ; the fourth output is produced by Call 2, which prints 0 ; and the fifth output
is produced by Call 1, which prints 1 . Thus, the output of the statement:

decToBin(13, 2);
is:

01101
The following Java program tests the method decToBin :

//*********************************************************
// Author: D.S. Malik
//
// Recursion: Program - Decimal to Binary
// This program uses recursion to find the binary
// representation of a nonnegative integer.
//*********************************************************

import java.util.*;

public class DecimalToBinary
{

static Scanner console = new Scanner(System.in);

public static void main(String[] args)
{

int decimalNum;
int base;

base = 2;

System.out.print("Enter a nonnegative integer in "
+ "decimal: ");
decimalNum = console.nextInt();
System.out.println();

System.out.print("Decimal " + decimalNum + " = ");
decToBin(decimalNum, base);
System.out.println(" binary");

}

1
3

public static void decToBin( int num, int base)
{

if (num == 0)
System.out.print(0);
else if (num > 0)
{

decToBin(num / base, base);
System.out.print(num % base);

}

}

}