How to Print Binary of a Decimal Number

[lokanath60]

Any one Write this Program in a Better Way ..

/*******
*@Author Lokanath Behera
*@Mob-[removed]
*@Email-[removed]@gmail.com
*****/
 
class Binary{
    public static void main(String[] args){
        int no=19999;
        int i=0;
        int size=no/2;
        int a[]=new int[++size];
        while(no>0){
 
        if(no%2==0){
            a[i++]=0;
        }
        else{
            a[i++]=1;
 
        }
        no /=2;
        }
 
        for(int j=i-1;j>=0;j--){
 
            System.out.print(a[j]);
 
        }
    }
}
 

[Nepomuk]

Define better. For example, an elegant way would be to do it recursively.
Even keeping with the loop approach, the length of the array can be calculated more accurately with

// The length will be the logarithm of no to base 2, plus 1
int size = Math.log(no) / Math.log(2) + 1;

There are also ways to calculate logarithms to the base 2 more efficiently, so you could use those if efficiency is relevant.
Does that cover it or is there a specific way in which you want it improved?

[vijay6]

Hey lokanath60, there is no need of if-else statement inside the while loop.

[Nepomuk]

Good point, you could just use

while(no > 0){
  a[i++] = no % 2;
  no /=2;
}

[Sherin]

Try This Code

public class BinaryDecimal {
 
    public static void main(String[] args) {
        long num = 110110111;
        int decimal = convertBinaryToDecimal(num);
        System.out.printf("%d in binary = %d in decimal", num, decimal);
    }
 
    public static int convertBinaryToDecimal(long num)
    {
        int decimalNumber = 0, i = 0;
        long remainder;
        while (num != 0)
        {
            remainder = num % 10;
            num /= 10;
            decimalNumber += remainder * Math.pow(2, i);
            ++i;
        }
        return decimalNumber;
    }
}