Java Program to Count set bits in an integer

// Java program to Count set
// bits in an integer
import java.io.*;

class countSetBits {
    /* Function to get no of set 
    bits in binary representation 
    of positive integer n */
    static int countSetBits(int n)
    {
        int count = 0;
        while (n > 0) {
            count += n & 1;
            n >>= 1;
        }
        return count;
    }

    // driver program
    public static void main(String args[])
    {
        int i = 9;
        System.out.println(countSetBits(i));
    }
}

// This code is contributed by Anshika Goyal.

// Java implementation of recursive
// approach to find the number
// of set bits in binary representation
// of positive integer n
import java.io.*;

class GFG {

    // recursive function to count set bits
    public static int countSetBits(int n)
    {

        // base case
        if (n == 0)
            return 0;

        else

            // if last bit set add 1 else add 0
            return (n & 1) + countSetBits(n >> 1);
    }

    // Driver code
    public static void main(String[] args)
    {

        // get value from user
        int n = 9;

        // function calling
        System.out.println(countSetBits(n));
    }
}

// This code is contributes by sunnysingh