Thread: Variable Scope

Hi All,

This is my question:

Write a function that counts the number of times it is called. Name the function count_it(). Do not pass it anything. In the body of count_it(), print the following message:

The number of times this function has been called is: ###

where ### is the number. (Hint: Because the variable must be local, make it static and initialize it to zero when you first define it.)


Here is what I did... Is there any way to make it better? different way?

Thank you

Code:

#include <iostream>
using namespace::std;

count_it(); //prototypes
second();

main()
{
count_it();
second();
return 0;
}


count_it() // this function counts how many time it has been called
{
static int count = 0;
count++;
cout << "The number of times this function has been called is " << count << "\n";

return 0;
}

second() //another function that calls count_it() 
{
	count_it();
return 0;
}

Hi,

1) Specify the return type of your functions.

2) To better demonstrate what your count_it() function does, create a for loop in main() that loops 10 times, and inside the for loop call count_it().

I see no reason for the second() function. If you want to make it call twice, just call count_it() twice. If you don't want to pass a variable, and keep the variable locally in the function, I don't see many other ways you can do it. However, there's some more complicated ways to do it without passing anything to the function, but using a global variable.

Code:

unsigned long count_it()
{
  static unsigned long count = 0;
  ++count;
  cout << "The number of times this function has been called is " << count << "\n";

  return count;
}

Unsigned int is a lot nicer for counters than a signed int.

Returning the count is a nice convenience feature. I would actually make a class to wrap the counting and allow access to count.

For example:

Header:

Code:

class CallCounter
{
public:
  static unsigned int increment() { return ++m_count; }
  static unsigned int getCount() const { return m_count; }
  static void reset() { m_count = 0; }

private:
  static unsigned int m_count;
};

Source:

Code:

unsigned int CallCounter::m_count(0);

Usage:

Code:

void myFunc1()
{
  CallCounter::increment();
}

void myFunc2()
{
  std::cout << "Called " << CallCounter::increment() << "times." << std::endl;
}

void myFuncReport()
{
  std::cout << "Total called " << CallCounter::getCount() << "times." << std::endl;
}

int main()
{
  myFunc1();
  myFunc2();
  //...
  myFuncReport();

  return 1;
}