C++ Primer 8.2

8.2.cpp

#include <iostream>
#include <cstring>

const int MAX_STR_LEN = 255;

struct CandyBar
{
  char brand[MAX_STR_LEN];
  double weight;
  int calorie;
};

void set_candy_bar(CandyBar & candy_bar, const char * brand, double weight, int calorie);
void show_candy_bar(const CandyBar & candy_bar);

int main()
{
  CandyBar sample_candy_bar = {"Millenium Munch", 2.85, 350};

  show_candy_bar(sample_candy_bar);
  set_candy_bar(sample_candy_bar, "New Munch", 3.0, 400);
  show_candy_bar(sample_candy_bar);

  return 0;
}

void set_candy_bar(CandyBar & candy_bar, const char * brand, double weight, int calorie)
{
  strncpy(candy_bar.brand, brand, sizeof(candy_bar.brand) -1);
  candy_bar.weight = weight;
  candy_bar.calorie = calorie;
}

void show_candy_bar(const CandyBar & candy_bar)
{
  using namespace std;

  cout << "-- output --" << endl;
  cout << "brand: " << candy_bar.brand << endl;
  cout << "weight: " << candy_bar.weight << endl;
  cout << "calorie: " << candy_bar.calorie << endl;
}