std::array<T,N>::back - cppreference.com (original) (raw)

reference back(); (1) (since C++11) (constexpr since C++17)
const_reference back() const; (2) (since C++11) (constexpr since C++14)

Returns a reference to the last element in the container.

If empty() is true, the behavior is undefined. (until C++26)
If empty() is true: If the implementation is hardened, a contract violation occurs. Moreover, if the contract-violation handler returns under “observe” evaluation semantic, the behavior is undefined. If the implementation is not hardened, the behavior is undefined. (since C++26)

[edit] Return value

Reference to the last element.

[edit] Complexity

Constant.

[edit] Notes

For a non-empty container c, the expression c.back() is equivalent to *std::prev(c.end()).

[edit] Example

#include #include   int main() { std::array<char, 4> letters{'a', 'b', 'c', 'd'}; assert(letters.back() == 'd'); }

[edit] See also

| | access the first element (public member function) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns a reverse iterator to the beginning (public member function) [edit] | | | returns an iterator to the end (public member function) [edit] |