text: #include "question.h"
  #include "choice_question.h"
  #include <iostream>
  using namespace std;
  
  int main()
  {
  	question q1;
  	q1.set_text("what is the capitol of Oklahoma?");
  	q1.set_answer("Oklahoma City");
  	q1.display();
  	string response;
  	getline(cin, response);
  	cout << boolalpha;
  	cout << q1.check_answer(response) << endl;
  
  	question q2;
  	q2.set_text("Which language is used in programming II class?");
  	q2.set_answer("C++");
  	q2.display();
  	getline(cin, response);
  	cout << q2.check_answer(response) << endl;
  
  	choice_question q3;
  	q3.set_text("Which programming language is not used in our department?");
  	q3.add_choice("C++", false);
  	q3.add_choice("Java", false);
  	q3.add_choice("Fortran", true);
  	q3.add_choice("C#", false);
  	q3.add_choice("Javascript", false);
  
  	q3.display();
  	getline(cin, response);
  	cout << q3.check_answer(response) << endl;
  
  	//q2 = q3; // OK
  	// q3=q2; //ERROR sub = super
  
  	question *pq = &q2;
  	choice_question *pcq = &q3;
  
  	//pcq = pq; // ERROR!
  	pq = pcq; // OK!
  
  	cout << endl << endl;
  	pcq->display();
  
  	cout << "-------------------" << endl << endl;
  	question* quiz[4];
  	quiz[0] = &q1;
  	quiz[1] = &q2;
  	quiz[2] = &q3;
  
  	choice_question q4;
  	q4.set_text("What is 2 + 3 = ?");
  	q4.add_choice("1",false);
  	q4.add_choice("2",false);
  	q4.add_choice("3",false);
  	q4.add_choice("5",false);
  	quiz[3] = &q4;
  
  	cout << "Quiz started!" << endl;
  	for (int i = 0; i < 4; i++)
  	{
  		cout<<"Q"<< (i+1) << ": ";
  		quiz[i]->display();
  		getline(cin,response);
  		cout << "Yout answer is:" << quiz[i]->check_answer(response) << endl;
  		cout << "----------" << endl;
  	}
  }