convert decimal to binary recursive java return string code example

Example 1: Decimal number to binary in java using recursion

public class DecimalToBinaryUsingRecursion
{
   public static void main(String[] args)
   {
      int inputDecimal = 50;
      System.out.println(toBinary(inputDecimal));
   }
   static int toBinary(int decimal)
   {
      if(decimal == 0)
         return 0;
      else
         return(decimal % 2 + 10 * toBinary(decimal / 2));
   }
}

Example 2: convert decimal to binary in java

public class DecimalToBinaryExample2{    
public static void toBinary(int decimal){    
     int binary[] = new int[40];    
     int index = 0;    
     while(decimal > 0){    
       binary[index++] = decimal%2;    
       decimal = decimal/2;    
     }    
     for(int i = index-1;i >= 0;i--){    
       System.out.print(binary[i]);    
     }    
System.out.println();//new line  
}    
public static void main(String args[]){      
System.out.println("Decimal of 10 is: ");  
toBinary(10);    
System.out.println("Decimal of 21 is: ");  
toBinary(21);    
System.out.println("Decimal of 31 is: ");    
toBinary(31);  
}}