scanf example:

#include <stdio.h>
#include <math.h>

int main( void)
{
  int n, count;
  double x, y;

  count = scanf( "%lf%i", &x, &n);

  printf( "count = %i\n", count);

  y = pow( x, n);

  printf( "x = %g, n = %i, y = %g\n", x, n, y);

  return 0;
}

& address-of operator, e.g. &x could be 100, &n could be 108:

sample runs:

input		output
-----           ------
		count = -1
		x = 1.40178e-307, n = 134514009, y = 0

abc		count = 0
		x = 7.6521e-308, n = 134514009, y = 0

1.1 abc		count = 1
		x = 1.1, n = 134514009, y = inf

1.1 2		count = 2
		x = 1.1, n = 2, y = 1.21

Each % format acts like a placeholder for a value to be read:

primary formats:

  char      %c
  int       %i
  double    %lf

Table 2.7, page 47: