For and Foreach
#include <iostream>
#include <vector>
#include <algorithm>

void f(int &n)//pass by reference
//void f(int n)//pass by value
{
	n *= 10;
}

int main(int argc, char *argv[])
{
	std::vector<int> c = {1, 2, 3, 4};

	//for
	for(int i = 0; i < c.size(); i++)
		c[i] *= 10;

	//foreach
	for(auto &e : c)//pass by reference
	//for(auto e : c)//pass by value
		e *= 10;

	//for_each in algorithm library
	for_each(c.begin(), c.end(), f);

	//display
	for(int i = 0; i < c.size(); i++)
		std::cout<<c[i]<<" ";
	std::cout<<std::endl;

	return 0;
}