TPS 12: Reading from a file
- Due Apr 21, 2021 by 10am
- Points 1
- Submitting a file upload
- File Types doc and docx
- Available after Apr 21, 2021 at 9am
Consider the following program (a version of TPS11 that reads in from a file instead of the user) and complete the three TODOs.
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//============================================================================== // File: tps12.cpp // Author: Hank Feild // Date: 14-Apr-2021 // Purpose: Demonstrates reading in data from a file. //============================================================================== #include <iostream> #include <fstream> #include <vector> using namespace std; struct Car { string make, model; int year, miles; bool has4WheelDrive; }; /** * Reads in a car's information from the given input file stream. Data in the * file is expected to be in this format (one piece of data per line) * * make * model * year * miles * 2WD (yes/no) * * @param fin The input file stream to read the data from. * @return A Car populated with the next chunk of data from the input stream. */ Car ReadCarFromFile(ifstream &fin){ Car car; string fourWheelDriveResponse; // TODO 1: below is the code we used to read in info about a car from // the user. Adapt this to read in from the input file (fin). Do we // need the prompts? cout << "Please enter the following data about the car:" << endl; cout << "Make (Ford/Toyota/etc.): "; getline(cin, car.make); cout << "Model (F-150, Corolla, etc.): "; getline(cin, car.model); cout << "Year: "; cin >> car.year; cout << "Miles: "; cin >> car.miles; cin.ignore(); cout << "Does it have 4WD? [yes/no]: "; getline(cin, fourWheelDriveResponse); car.has4WheelDrive = fourWheelDriveResponse == "yes"; return car; } /** * Prints out a Car in a nice format: * * <year> <make> <model> with <miles> miles with<out?> 4-wheel drive * * @param car The Car to display. */ void PrintCar(Car car){ cout << car.year << " " << car.make << " " << car.model << " with " << car.miles << " miles with"; if(!car.has4WheelDrive){ cout << "out"; } cout << " 4-wheel drive" << endl; } /** * Asks the user for three cars, then prints them out. * * @return The exit status of the program; 0 is good. */ int main(){ vector<Car> cars; ifstream fin; string filename; Car car; cout << "Enter the name of the file with car data: "; getline(cin, filename); // TODO 2: Open the file for reading (the variable `filename` has the name // of the file and `fin` is our input file stream variable). // Check if it opened okay; we can exit if it didn't. if(!fin.is_open()){ cout << "The file could not be opened."; exit(1); } // Read all the cars in from the file. while(fin.good()){ // TODO 3: the invocation of ReadCarFromFile is missing an argument; fix it. car = ReadCarFromFile(); // Only add the car if all of its data was read in without error // (fin.good() will be true if there were no errors). if(fin.good()){ cars.push_back(car); } } // Close the file -- always do this once you're finished with a file. fin.close(); // Add 10 miles to each car. for(int i = 0; i < cars.size(); i++){ cars.at(i).miles += 10; } // Print the cars. for(int i = 0; i < cars.size(); i++){ PrintCar(cars.at(i)); } return 0; } |
After we've completed the group share portion, upload a copy of your updated TPS document.