Check if all bits of a number are set in c

C program for Check if all bits of a number are set. Here more information.

// Include header file
#include <stdio.h>

/*
  C program for
  Check if all bits of a number are set or active
*/
// Determine that given number 
// contains all active bits or not
void isActiveBits(int num)
{
	printf("\n Number : %d\n", num);
	if (num != 0 && ((num + 1) & num) == 0)
	{
		// When all set bit exist in given number
		printf(" Yes\n");
	}
	else
	{
		printf(" No\n");
	}
}
int main()
{
	// Test A
	// (-1) Binary 0001 => 1110 (1's) => 1111 (2s)
	isActiveBits(-1);
	// Test B
	// (-4) 00000100 = > 11111011 (1s) => 11111100 (2s)
	isActiveBits(-4);
	// Test C
	// (15) 1111 => Yes
	isActiveBits(15);
	// Test D
	// (100) 1100100 
	isActiveBits(100);
}

Output

 Number : -1
 Yes

 Number : -4
 No

 Number : 15
 Yes

 Number : 100
 No