How do you write a C plus plus program for calculating the sum of even numbers entered by user using static data and static member functions?

Answer 1

#include<iostream>

#include<vector>

class foo {

private:

static std::vector<size_t> evens;

public:

static bool add_number (size_t num);

static size_t sum();

static std::vector<size_t>& get_evens () { return evens; }

};

bool foo::add_number (size_t num) {

if ((num%2)==0) { evens.push_back (num); return true; }

return false;

}

size_t foo:sum () {

size_t sum {0};

for (auto num : evens) sum+= num;

return sum;

}

int main () {

size_t in;

while (std::cin >> in) {

foo::add_number (in);

}

for (auto num : foo::get_evens()) std::cout << num << std::endl;

std::cout << "Sum = " << foo::sum() << std::endl;

}