CS 10 SI Classroom Session 2 - Example 2

input1.txt

237.87
9.52

input2.txt

twelve
sixteen

main.cpp

#include <iostream>

using namespace std;

int main() {
  // Again, it is only acceptable to leave built-in types uninitialized
  // if you solely plan to fill them with user input. Even then, you should
  // be safe and initialize them to default values.
  double milesTraveled;
  double gallonsUsed;

  // From the user's side, what's wrong with just asking for input like this?
  //
  // On the other hand, from the developer's side, what assumptions are you
  // making that makes this okay?
  cin >> milesTraveled;
  cin >> gallonsUsed;

  // There could be an error here.
  // 1. What type of error is it?
  // 2. What values trigger it?
  // 3. What does the program do if you use those values?
  double milesPerGallon = milesTraveled / gallonsUsed;
  
  // What's better?
  // 1. cout << milesPerGallon
  // 2. cout << milesTraveled / gallonsUsed
  // Why?
  cout << "You averaged " << milesPerGallon << " MPG." << endl;

  return 0;
}