//To compile: g++ [source_code.cpp] -o [exec_file]
// replace [soure_code.cpp] with the filename, 
// replace [exec_file] with the executable file name
// i.e., g++ c++_basics.cpp -o run
//Note: if the output redirect is not given, i.e., the "-o [exec_file]" part is missing
//      then the default executable name is a.out

//To run the program, simply run the executable: ./[exec_file]
// i.e., ./a.out  (if your executable file is a.out)

#include <iostream> //input/output stream library

using namespace std; 


void swap_val(int x, int y){
	int temp = x;
	x = y;
	y = temp;

	cout << "x: " << x << endl;
	cout << "y: " << y << endl;

	//print out addr of x and y
	cout << "&x: " << &x << endl;
	cout << "&y: " << &y << endl;
}

void swap_ref(int &x, int &y){
	int temp = x;
	x = y;
	y = temp;
	cout << "x: " << x << endl;
	cout << "y: " << y << endl;

	//print out addr of x and y
	cout << "&x: " << &x << endl;
	cout << "&y: " << &y << endl;
}

//main function: entry point of the program
int main()
{
// 	//declare and initialize the variable, grade
// 	int grade = 0; 

// 	int again = -1;

// 	//prompt the user for an input, and store it into 'grade'
// 	do {

// 		cout << "Enter your grade: ";
// 		cin >> grade;

// 		//output the grade to the console
// 		// endl: end of the line
// 		cout << "Your grade is: " << grade << endl;

// 		if (grade >= 90)
// 			cout << "A" << endl;
// 		else if (grade >= 80) 
// 			cout << "B" << endl;
// 		else if (grade >= 70) 
// 			cout << "C" << endl;
// 		else if (grade >= 60) 
// 			cout << "D" << endl;
// 		else 
// 			cout << "F" << endl;


// 		cout << "Would you like to enter a different grade? 1-yes, else-no: ";
// 		cin >> again;
// 	} while (again == 1);


	int a = 5, b = 10;

	//swap_val(a, b);
	swap_ref(a, b);

	cout << "a: " << a << endl;
	cout << "b: " << b << endl;

	//print out addr of a and b
	cout << "&a: " << &a << endl;
	cout << "&b: " << &b << endl;


	return 0;
}