// Lab 12 Lecture

// Refer to the provided notes for further explanation of the following
// examples.

// I have included several programs in the same file. Comment out all
// programs except for the one you wish to run.
// (Eclipse: ctrl+/ to comment and uncomment)
// (Code Blocks: ctrl+shift+C to comment and ctrl+shift+x to uncomment)


// ----------------------------- Structs --------------------------------------

//// "C++ allows you to group several variables together under a single item
//// known as a structure." -Tony Gaddis, Starting Out With C++
//
//#include <iostream>
//using namespace std;
//
//// Struct Definition (Think blueprint)
//struct StudentRecord
//{
//	// Member Variables
//	int studentID;
//	string firstName;
//	string lastName;
//	double gpa;
//};		// the semicolon is required
//
//
//int main()
//{
//	// Variable Declaration (or more accurately object declaration)
//	//
//	// like "string", "StudentRecord" is an abstract data type
//	// and so we must create an instance of it when we want to use one.
//	// Here "StudentRecord" is our abstract data type and "student" is
//	// the name of our newly created object. 
//	//
//	// You can think of an object as being similar to a variable, but 
//	// while a variable contains only a single piece of data, an object
//	// is comprised of multiple pieces of data with often different 
//	// data types (later you will learn they also can contain functions).
//
//	StudentRecord student;
//
//	// Accessing an object's Members
//	//
//	// we use the dot operator (.) to access member variables. 
//	// syntax : objectName.memberName
//
//	student.studentID = 12321;
//	student.firstName = "John";
//	student.lastName = "Snow";
//	student.gpa = 3.76;
//
//	cout << student.studentID << endl
//			<< student.firstName << endl
//			<< student.lastName << endl
//			<< student.gpa << endl;
//
//	return 0;
//}


// ---------------------- Initializing a Struct -------------------------------

//// Declaring and Initializing at the same time
//
//#include <iostream>
//using namespace std;
//
//// Struct Definition
//struct Time
//{
//     int hour;
//     int minutes;
//     int seconds;
//};
//
//int main()
//{
//	// Struct Object Declaration and Initialization
//	Time myTime = {12, 32, 45};
//
//	cout << myTime.hour << ":" << myTime.minutes << "." << myTime.seconds;
//}


// ------------------------- Arrays of Objects --------------------------------

//#include <iostream>
//using namespace std;
//
//// Struct Definition
//struct StudentRecord
//{
//	  // Members
//    int studentID;
//    string firstName;
//    string lastName;
//    double gpa;
//};
//
//
//int main()
//{
//	// Array of Objects Declaration
//	StudentRecord student [10000];
//
//	// Accessing members of an array of structs
//	student[0].firstName = "Cersei";
//	student[0].lastName = "Lannister";
//	student[0].studentID = 543345;
//	student[0].gpa = 3.9;
//
//	cout << student[0].studentID << endl
//			<< student[0].firstName << endl
//			<< student[0].lastName << endl
//			<< student[0].gpa << endl;
//
//	return 0;
//}


// --------------------- Structs With Member Arrays ---------------------------

//#include <iostream>
//using namespace std;
//
//// Struct Definition
//struct StudentRecord
//{
//	  // Members
//    string firstName;
//    string lastName;
//    int testGrades[4]; // We can have members that are arrays
//};
//
//
//int main()
//{
//	// Array of Objects Declaration
//	StudentRecord student [10000];
//
//	cout << "Enter student's first name" << endl;
//	cin >> student[0].firstName;
//
//	cout << "Enter student's last name" << endl;
//	cin >> student[0].lastName;
//
//	cout << "Enter the student's 4 test grades" << endl;
//
//	// Here we use a FOR loop to get each grades for student "0".
//	// Note that this will only fill the array for student "0".
//	for(int i = 0; i < 4; i++)
//	{
//		cin >> student[0].testGrades[i]; 
//	}	
//
//
//	return 0;
//}

// note that this code only assigns values to 1 of the 10000 StudentRecord
// array elements that we created. To fill the other values we would have to 
// use another loop to repeat this code for the other students.


// -------------------------- Structs Example  --------------------------------

//// Reads in students from user (keyboard) into an array
//// of structs and outputs them to a file.
//
//
//#include <iostream>
//#include <fstream>
//using namespace std;
//
//// Struct Definition
//struct StudentRecord
//{
//    int studentID;
//    string firstName;
//    string lastName;
//    double gpa;
//};
//
//
//int main()
//{
//	// Variable Array Declaration
//	StudentRecord student [1000];
//	int count;
//	char userChoice;
//
//	ofstream fout;
//	// We can set our ofstream to append to the end of the file so we do not
//	// lose previously entered data by using std::ofstream::app as demonstrated.
//	// This is just for your knowledge and will not be tested over.
//	fout.open("StudentData.txt", std::ofstream::app);
//
//	count = 0;
//
//	// Take student info from user and put it into array the array of Structs.
//	do{
//		cout << "Enter Student ID : ";
//		cin >> student[count].studentID;
//
//		cout << "Enter Student's First Name : ";
//		cin >> student[count].firstName;
//
//		cout << "Enter Student's Last Name : ";
//		cin >> student[count].lastName;
//
//		cout << "Enter Student's GPA";
//		cin >> student[count].gpa;
//
//		cout << "Are you finished? (Y or y)" << endl;
//		cin >> userChoice;
//		cout << endl;
//
//		count++;
//	}while(userChoice != 'Y' && userChoice != 'y');
//
//
//	for(int i=0; i<count; i++)
//	{
//		fout << student[i].studentID << " " << student[i].firstName
//				<< " " << student[i].lastName << " " << student[i].gpa
//				<< endl;
//	}
//
//	fout.close();
//
//	return 0;
//}