Control Structures: Difference between revisions

#include <iostream> // std::cout, std::endl

#include <vector> // std::vector

#include <algorithm> // std::for_each

struct sum

{

int _sum;

sum() : _sum(0) {}; // Initialize sum with 0;

void operator() (int a) { _sum += a; } // this function will be called for every element

};

int main()

{

std::vector<int> v;

v.push_back(10);

v.push_back(23);

v.push_back(34);

/* Note that for_each gets a fresh instance of sum passed,

* applies every element beginning with *v.begin() up to,

* but not including v.end() to the function object

* and returns a copy of it.

*/

sum the_sum = std::for_each(v.begin(), v.end(), sum());

std::cout << "The sum is " << the_sum._sum << std::endl;

return 0;

}