count set bits in a number in cpp code example

Example 1: Count set bits in an integer c++

//Method 1
	int count = __builtin_popcount(num);
//Method 2
	int count = 0;
    while (num) {
        count += num & 1;
        n >>= 1;
    }

Example 2: count bits c++

//Method 1
   int count = 0;
   while (n)
   {
        count++;
        n >>= 1;
    }
//Method 2
	int count = (int)log2(number)+1;