Thread: Comparing two time programs

Okay, this simple program works just fine:

Code:

#include <iostrem>
#include <ctime>
using namespace std;

int main()
{

  time_t myTime;
  time ( &myTime );
  printf ( "Current date and time are: %s", ctime (&myTime) );

 return 0;
}

Yet this one doesn't (it compiles but doesn't return anything):

Code:

#include <iostream>
#include <ctime> 
using namespace std;

class Date 
{
   public:
      Date();  
      ~Date();  
	
   private:
      int myTime;


}; // end class Date

Date::Date()
{
  time_t myTime;
  time ( &myTime );
  printf ( "Current date and time are: %s", ctime (&myTime) );
}

int main(){

   Date h();
  
   return 0;
}

As you can see, I'm trying to create a constructor to do the same thing that the first program does. Any info is greatly appreciated!

http://www.parashift.com/c++-faq-lit....html#faq-10.2

Code:

#include <cstdio>
#include <ctime> 
using namespace std;

class Date 
{
   time_t myTime;
public:
   Date() : myTime ( time ( NULL ) )
   {
      printf ( "Current date and time are: %s\n", ctime (&myTime) );
   }
};

int main()
{
   Date h;
   return 0;
}

Great link, thanks a lot!

Another question - is it possible to use strcpy to copy Date h into a string? I'm getting conversion errors ie "cannot convert parameter from class Date to char *"

Code:

   strcpy ( timeToConvert, h ); // copy system time into timeToConvert

Context is wonderful.

Code:

#include <cstdio>
#include <ctime> 
#include <string>

class Date 
{
   std::time_t myTime;
   std::string text;
public:
   Date() : myTime ( std::time ( 0 ) ), text ( std::ctime ( &myTime ) )
   {
      std::printf ( "Current date and time are: %s\n", text.c_str() );
   }
};

int main()
{
   Date h;
   return 0;
}

/* my output
Current date and time are: Mon Apr 10 16:58:56 2006
*/

Oops, here is an example, since we haven't covered <string> just yet:

Code:

#include <iostream>
#include <ctime> // for time
#include <cstring> // for strings

using namespace std;

class Date 
{
   time_t myTime;

public:
   Date() : myTime ( time ( NULL ) )
   {
      printf ( "Current date and time are: %s\n", ctime (&myTime) );
   }

}; // end class Date

int main()
{
   Date h;

   string timeToConvert[30];
   char *tokenPtr;
   strcpy ( timeToConvert, h ); // copy system time into timeToConvert
   cout << timeToConvert;
   tokenPtr = strtok( timeToConvert, " ");
   while (tokenPtr !=NULL) {
      cout << tokenPtr << '\n';
	  tokenPtr = strtok(NULL, " "); // get next token

   } // end while

   cout << "\nAfter tokenizing, timeToConvert is: " << timeToConvert << endl;
  
  
  return 0;
}

The error is "Cannot convert parameter 1 from class to char *".

>> string timeToConvert[30];

c++ strings do not work like c-strings. This statement is declaring an array of 30 string objects. You must now learn how the c++ strings work. they work differently from c-strings so all the strcpy, strcmp and those functions no longer apply. Check this link http://www.cprogramming.com/tutorial/string.html

[edit]
Sorry, had inserted a wrong link, please check the new one
[/edit]

You'd need some public method to get at the private myTime value in the class Date. Something along this line.

Code:

char *Date::foo()
{
   return asctime(localtime(&myTime));
}

Then you'd need to copy the text pointed to by the pointer returned by this function to a char array.

Code:

   char timeToConvert[30];
   strcpy ( timeToConvert, h.foo() ); // copy system time into timeToConvert