std::vector<T,Allocator>::rbegin, std::vector<T,Allocator>::crbegin

reverse_iterator rbegin();
(until C++11)
reverse_iterator rbegin() noexcept;
(since C++11)
(until C++20)
constexpr reverse_iterator rbegin() noexcept;
(since C++20)
const_reverse_iterator rbegin() const;
(until C++11)
const_reverse_iterator rbegin() const noexcept;
(since C++11)
(until C++20)
constexpr const_reverse_iterator rbegin() const noexcept;
(since C++20)
const_reverse_iterator crbegin() const noexcept;
(since C++11)
(until C++20)
constexpr const_reverse_iterator crbegin() const noexcept;
(since C++20)

Returns a reverse iterator to the first element of the reversed vector. It corresponds to the last element of the non-reversed vector. If the vector is empty, the returned iterator is equal to rend().




Return value

Reverse iterator to the first element.




#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";


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

See also

returns a reverse iterator to the end
(public member function)
returns a reverse iterator to the beginning of a container or array
(function template)

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