Difference between revisions of "cpp/container/vector/begin"

#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <vector>
 
int main()
{
    std::vector<int> nums{1, 2, 4, 8, 16};
    std::vector<std::string> fruits{"orange", "apple", "raspberry"};
    std::vector<char> empty;
 
    // Print vector.
    std::for_each(nums.begin(), nums.end(), [](const int n) { std::cout << n << ' '; });
    std::cout << '\n';
 
    // Sums all integers in the vector nums (if any), printing only the result.
    std::cout << "Sum of nums: "
              << std::accumulate(nums.begin(), nums.end(), 0) << '\n';
 
    // Prints the first fruit in the vector fruits, checking if there is any.
    if (!fruits.empty())
        std::cout << "First fruit: " << *fruits.begin() << '\n';
 
    if (empty.begin() == empty.end())
        std::cout << "vector 'empty' is indeed empty.\n";
}

#include <iostream>
#include <vector>
 
int main()
{
	std::vector<int> ints {1, 2, 4, 8, 16};
	std::vector<std::string> fruits {"orange", "apple", "raspberry"};
	std::vector<char> empty;
 
	// Sums all integers in the vector ints (if any), printing only the result.
	int sum = 0;
	for (auto it = ints.cbegin(); it != ints.cend(); it++)
		sum += *it;
	std::cout << "Sum of ints: " << sum << "\n";
 
	// Prints the first fruit in the vector fruits, without checking if there is one.
	std::cout << "First fruit: " << *fruits.begin() << "\n";
 
	if (empty.begin() == empty.end())
		std::cout << "Vector 'empty' is indeed empty.\n";
	else
		std::cout << "Vector 'empty' has " << empty.size() << " elements.\n";
}