Static variables in static function

Static variables in functions
When a variable is declared as static when , Space will be allocated throughout the life cycle of the program . Even if the function is called multiple times , The space of static variables is allocated only once , The value of the variable in the previous call is passed through the next function call . This is true of C / C ++ Or any other application that needs to store the state of a previous function .

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

void demo()
{
    
        // static variable 
        static int count = 0;
        cout << count << " ";

        // value is updated and 
        // will be carried to next 
        // function calls 
        count++;
}

int main()
{
    
        for (int i=0; i<5; i++)
                demo();
        return 0;
}

Output ：

0 1 2 3 4