std::array<T,N>::back

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library (C++17)

Concurrency support library (C++11)

Execution control library (C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

hive (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::array

Member types
Member functions
Element access array::at array::operator[]    array::front array::back array::data Operations array::fill array::swap	Iterators array::beginarray::cbegin array::endarray::cend array::rbeginarray::crbegin    array::rendarray::crend	Capacity array::empty array::size array::max_size
Non-member functions
operator==operator<=> (C++20) get(std::array) swap(std::array) to_array (C++20)	operator|=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Helper classes
tuple_size<std::array>
tuple_element<std::array>
Deduction guides (C++17)

 

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

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. If the implementation is not hardened, the behavior is undefined.	(since C++26)

Return value

Reference to the last element.

Complexity

Constant.

Notes

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

Example

Run this code

#include <cassert>
#include <array>

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

See also

front	access the first element (public member function)
rbegincrbegin	returns a reverse iterator to the beginning (public member function)
endcend	returns an iterator to the end (public member function)