/*
 * Chapter3, Assignment 4.
 * By John Stile
 *   Write a function called dif2 that accepts 2 floating point arguments,
 *   subtracts the first from the second,
 *   and then output the difference.
 *   Put the function in a program and make it work.
 *   Comment the code.
 *   Program is called Assignment.problem4.Ch3.c
 */
#include <stdio.h> // include functions in stdio.h when compiling.

void dif2(float xx, float yy) // header for function dif2, takes 2 floats refered to as xx and yy, returns nothing.
{
  float zz;  // declare floating point variable zz
  zz=xx-yy;  // assign zz the difference between the values in xx and yy.
  printf("%f\n", zz); // print the resulting value in zz.
}  // end function  

int main(void) // header for function main.  takes nothing, returns an integer
{
  float vv, ww; // declare floating point variable vv and ww.
  printf ("Enter first floating point number. " ); // Ask user to enter number
  scanf("%f", &vv); // store the number input at the memory address of pointed to by vv
  printf ("Enter second floating point number. " ); // Ask user to enter number
  scanf("%f", &ww); // store the number input at the memory address of pointed to by ww
  dif2( vv, ww); // Call the function dif2, sending it the value stored in vv and ww.

  return 0;  // return a value of 0 to the colling program.
}