Your goal is to create, use, and test a Timer class. A Timer object should basically be equivalent to a stopwatch. Like a stopwatch, you must be able to start the Timer, stop the Timer, and clear the Timer. In addition, you must be able to getTime from the Timer. At a minimum, your class must contain the following member functions: void start(); // Starts the Timer void stop(); // Stops the Timer void clear(); // Clears time on the Timer float getTime(); // Returns elapsed time in seconds

You are free to create additional member functions if you wish, however the ones listed above are the only member functions that should be public. Additional member functions would only be used to support the member functions above and therefore ought to be private as they would not be called externally by the user. Getting the time In order to provide the functionality of a timer, youll need to be aware of the current time. In the Timer.h file that I provide, you will find a private member function called now() that you can use to fetch the number of milliseconds that have passed since midnight on January 1, 1970. I wrote this code which uses the C++ chrono (time) library. With this now() method, you can get check the current time at two different points in time and subtract the older value (the start time) from the more recent value (the stop time) in order to find the difference between them (the elapsed time in microseconds). Please use this now() member function to get those snapshots of time to implement your Timer functionality. One note: be aware that the now() method returns a value relating to elapsed microseconds in 64-bit integer form (long long int). The getTime() method requires you to return elapsed seconds in float form. Therefore, be sure to convert from microseconds to seconds appropriately by dividing by your integer microsecond values by 1000000.0 (note the decimal point which allows the result also be a float). Use the support code and ideas I provide to write your own Timer class. Once completed, you should be able to create an instance of your class and invoke/use it in the following way inside of your ex 1.cpp file: #include #include // Gives us access to the sleep(int seconds) function #include "Timer.h" using namespace std; int main() { Timer t; t.start(); // Start the clock sleep(2); // Sleep for 2 seconds cout << t.getTime() << endl; // Should print approximately 2.0 sleep(1); // Sleep for 1 second t.stop(); // Stop the clock cout << t.getTime() << endl; // Should print approximately 3.0 t.clear(); // Reset the stopped clock cout << t.getTime() << endl; // Should print 0 return 0; }

below is the timer.h

#pragma once

#include

class Timer {

private:

// TODO: Put any private member variables you want here

public:

Timer() {

// TODO: Initialize any member variables you'd like here

}

void start() {

// TODO: Implement me

}

void stop() {

// TODO: Implement me

}

void clear() {

// TODO: Implement me

}

float getTime() {

// TODO: Implement me

return -1; // TODO: Change me!

}

private:

// A private member function that you may find useful as you implement

// the functions listed above. It fetches the number of microseconds that

// have passed since 12:00 AM on Jan 1, 1970

// Don't worry too much about how it works right now; just trust me! :)

long long int now() {

using namespace std::chrono;

duration t = system_clock::now().time_since_epoch();

return t.count();

}

// TODO: Put any additional private member functions you want here

};

and the ex_1.cpp

#include

#include // Gives us access to the sleep(int seconds) function

#include "Timer.h"

using namespace std;

int main() {

Timer t;

t.start(); // Start the clock

sleep(2); // Sleep for 2 seconds

cout << t.getTime() << endl; // Should print approximately 2.0

sleep(1); // Sleep for 1 second

t.stop(); // Stop the clock

cout << t.getTime() << endl; // Should print approximately 3.0

t.clear(); // Reset the stopped clock

cout << t.getTime() << endl; // Should print 0

return 0;

}