Classes

[kirby3422]

I am having issues with this program. I have to use a constrictor TallyCounter::TallyCounter(), to initialize the tally to 0. Then I have to write a program, function main, that
utilizes this class and demonstrates how it works by counting people and displaying the current value
This is my code right now could anyone help? I know my main issues are in int get_value and void clear I think. Thanks for any and all help.

  #include <iostream>
using namespace std;



class TallyCounter
{
 private:
 int tally; // private variable used in the class to hold the count 
 
 public:
 void count(int a)
 {
 	tally=a;
 	tally++;
 	
 } // void function to increments the counter by one
 void clear(); // void function to clear the tally to zero
 {
 tally.clear();	
 }

 
 int get_value(int counter)
 {
 return counter; // function to return the current tally value
}
 TallyCounter::TallyCounter(); // Constructor
};

int main()
{
	TallyCounter tallyObject;
	tallyObject.clear();
	tallyObject.count();
	tallyObject.get_value();
	

cout<<"Total: "<<get_value();
return 0;
}

[Flaze07]

I am pretty sure int does not have clear function...
besides you forgot to initialize your constructor you only declare it
also rather than

TallyCounter::TallyCounter();

it is

TallyCounter();

ant to directly initialize it

TallyCounter()
{
}

[Flaze07]

here is a link to class tutorial
http://www.cplusplus.com/doc/tutorial/classes/

with function too

http://www.cplusplus.com/doc/tutorial/functions/

[kirby3422]

Okay so now I am getting errors in my compiler telling me invalid use of TallyCounter::TallyCounter(); and get_value was not declared// okay i see that this in function main thats why i am getting the error so how would i get the total to be displayed in function main if I cant use get value?

#include <iostream>
using namespace std;



class TallyCounter
{
 private:
 int tally; // private variable used in the class to hold the count 
 
 public:
 void count()
 {

 	++tally;
 	
 } // void function to increments the counter by one
  // void function to clear the tally to zero
 

 
 int get_value(int counter)
 {
 return counter; // function to return the current tally value
}
TallyCounter();
{

 TallyCounter::TallyCounter(); // Constructor
}
};

int main()
{
	TallyCounter tallyObject;
	tallyObject.count();
	tallyObject.get_value();
	tallyObject.TallyCounter();
	

cout<<"Total: "<<get_value();
return 0;
}

[JLBorges]

#include <iostream>

struct tally_counter
{
    // default constructor: initialises tally to zero
    tally_counter() : tally(0) {}

    int get() const { return tally ; } // return the current tally


    void set( int value ) { tally = value ; } // set the tally to value
    void clear() { set(0) ; } // reset the tally to zero

    // add n to the tally. default value for n is one
    void count( int n = 1 ) { tally += n ; }

    private: int tally ;
};

int main()
{
    tally_counter counter ; // initialises tally to 0

    counter.count() ; // 0 + 1 == 1
    std::cout << counter.get() << '\n' ; // 1

    counter.count(5) ; // 1 + 5 == 6
    std::cout << counter.get() << '\n' ; // 6

    counter.clear() ; // reset tally to zero
    std::cout << counter.get() << '\n' ; // 0

    counter.count() ; // 0 + 1 == 1
    std::cout << counter.get() << '\n' ; // 1
}

[kirby3422]

Okay so i see how that works. How would I get this if the operator would push any key and advance the counter by 1 every time?

[JLBorges]

What do you mean by "push any key"?

[kirby3422]

So basically the program asks me to implement a class that models a tally counter, a device that is used to count people like to find out how many people attend a concert or board a bus. Whenever the operator pushes a button, the counter value advances by one

#include <iostream>
using namespace std;



class TallyCounter
{
 private:
 int tally; // private variable used in the class to hold the count 
 
 public:
 void count()
 {

 	++tally;
 	
 } // void function to increments the counter by one
  // void function to clear the tally to zero
 void set( int total) 
{ 
tally = total ; 
}
 
void clear()
{
	set(0);
}
 
 int get_value()const
 {
 return tally; // function to return the current tally value
}


 TallyCounter:tally(0)
 {
 } // Constructor

};

int main()
{
	
	TallyCounter counter;
	
	counter.get_value();
	cout<<counter.get_value()<<"/n";
	 


return 0;
}

Okay I also did not want to copy your code so I implemented it into mine but it is still telling me I have errors. What is wrong with these implements? oops I missed the set value. implemented that but it is still telling me that i have an improper use of the TallyCount(0)

[JLBorges]

// TallyCounter:tally(0)
TallyCounter() : tally(0)
{
} // Constructor 

[kirby3422]

Oh crap I am sorry that was a terrible error on my part lol. So do you understand what I am asking would I put a cout statement inside the get value function to get user input? I don't understand how you could get any button to count people without hitting enter. Or maybe even a while loop!? I appreciate all of your help.

[Flaze07]

there is a way but it is not standard C++
either this way or use an external library

#include <iostream>
#include <conio.h> //for getch()

int main()
{
   char input;
   do
   {
      input = getch(); //getch() directly is possible
   }while (input != 'e');
   std::cout << "yay, you pressed e\n'; 
} 

example of getch() directly

#include <iostream>
#include <conio.h>

int main()
{
   do 
   {
   }while (getch() != 'e);
} 

either that or use other librarier that provides key checking such as sfml

[Flaze07]

no, you dont need to put cout inside

[kirby3422]

How would that count the tally's though? When I input that all it lets me do is hit e and then prints yay you hit e. So basically I would need a way of hitting any key and the program print 1 2 3 4 and keep counting up until I stop it. I could see using a for loop possibly to set (tally=0, tally++) something similar?

[kirby3422]

I did something like

#include <iostream>
#include <conio.h>
using namespace std;



class TallyCounter
{
	
 private:
 int tally; // private variable used in the class to hold the count 
 
 public:
 void count()
 {
while(tally)
{

 	++tally;
}
 	
 } // void function to increments the counter by one
  // void function to clear the tally to zero
   void set( int total )
    {
    	
    	
		
	 tally = total;

	  }
 
void clear()
{
	set(0);
}
 
 int get_value()const
 {

	 
 return tally; // function to return the current tally value

}

TallyCounter() : tally(0)
{
} // Constructor 
 // Constructor

};

int main()
{
	TallyCounter counter;
 char input;
 
   do
   {
   	cout<<"Hit any letter to count people then hit e"<<endl;
      input =counter.get_value();
	  cin>>input; //getch() directly is possible
   }while (input!= 'e');
   cout << "yay, you pressed \n'"; 
	 
system("pause");

return 0;
}

But that just repeats the statement

[JLBorges]

#include <iostream>

struct tally_counter
{
    // default constructor: initialises tally to zero
    tally_counter() : tally(0) {}

    int get() const { return tally ; } // return the current tally


    void set( int value ) { tally = value ; } // set the tally to value
    void clear() { set(0) ; } // reset the tally to zero

    // add n to the tally. default value for n is one
    void count( int n = 1 ) { tally += n ; }

    private: int tally ;
};

int main()
{
    tally_counter counter ; // initialises tally to 0


    std::cout << "hit enter when a person boards the bus\n"
              << "end input with ctrl+D (unix/unix-clone) / ctrl+Z (windows)\n"
              << "or end program with ctrl+C (anywhere)\n" ;

    // while the user has hit enter and there stdin is not at eof
    while( std::cout << "? " && std::cin.get() && std::cin )
    {
        counter.count() ; // increment the tally
        std::cout << "current tally is " << counter.get() << '\n' ;
    }

}

[kirby3422]

I appreciate all the help you guys have given. I've never seen that ctrl+C method. Awesome thank you again!