Thread: How do you do time in C++?

I want to do time in C++. Not tell the user what the date is or what the time is now, but instead calculate how much time it takes to do something. I want to know how you do it or if there are any good tutorials on this general topic.

Thanks

Well, you need a function to get the current time. You call it before the block you want to time. You call it again afterwards. Then you take the difference.

time() is a possibility, but an inaccurate one, whereas clock() is more accurate, but on some implementations only measures actual CPU time. Other than that, there's only non-portable stuff, like the *nix gettimeofday() or the Win32 GetTickCount() or timeGetTime().

A bad one insofar as that you should never ever use gets. But it demonstrates the timing.

Originally Posted by CornedBee

A bad one insofar as that you should never ever use gets. But it demonstrates the timing.

Yeah - I just copied that straight from the other website. Here's a C++ version:

Code:

/* difftime example */
#include <iostream>
#include <string>
#include <time.h>

int main (void)
{
  time_t start,end;
  std::string name;
  double dif;

  time (&start);
  std::cout << "Please enter your name:" << std::endl;
  std::getline(std::cin, name);
  time (&end);
  dif = difftime (end,start);
  std::cout << "Hi "<< name << "." << std::endl;
  std::cout << "It took you " << dif << " seconds to type your name.\n";
 
  return 0;
}