Listing 11 Exposes the automatic conversions performed via prototypes

#include <stdio.h>

void f2( int,double);

main()
{
   f1(1.3);
   f1(1.0, 3.0);

   f2(1.3);
   f2(1.0,3.0);
   f2(1.0e6,3.0e6);
   return 0;
}

f1(x,y)
/* Old-style function declaration */
int x;
double y;
{
   printf("%d, %f\n",x,y);
}

void f2(int x, double y)
{
   printf("%d, %f\n",x,y);
}

/* Output:
1, 0.000000
1, 3.000000
1, 3.000000
1, 3.000000
16960, 3000000.000000
*/
/* End of File */