NAME

std::vector::rend,std::vector::crend - std::vector::rend,std::vector::crend

Synopsis

reverse_iterator rend(); (until C++11)
reverse_iterator rend() noexcept; (since C++11)
(until C++20)
constexpr reverse_iterator rend() noexcept; (since C++20)
const_reverse_iterator rend() const; (until C++11)
const_reverse_iterator rend() const noexcept; (since C++11)
(until C++20)
constexpr const_reverse_iterator rend() const noexcept; (since C++20)
const_reverse_iterator crend() const noexcept; (since C++11)
(until C++20)
constexpr const_reverse_iterator crend() const noexcept; (since C++20)

Returns a reverse iterator to the element following the last element of the reversed
vector. It corresponds to the element preceding the first element of the
non-reversed vector. This element acts as a placeholder, attempting to access it
results in undefined behavior.

range-rbegin-rend.svg

Parameters

(none)

Return value

Reverse iterator to the element following the last element.

Complexity

Constant.

Example

// Run this code

#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.rbegin(), nums.rend(), [](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.rbegin(), nums.rend(), 0) << '\n';

// Prints the first fruit in the vector fruits, checking if there is any.
if (!fruits.empty())
std::cout << "First fruit: " << *fruits.rbegin() << '\n';

if (empty.rbegin() == empty.rend())
std::cout << "vector 'empty' is indeed empty.\n";
}

Output:

16 8 4 2 1
Sum of nums: 31
First fruit: raspberry
vector 'empty' is indeed empty.