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std::vector<T,Allocator>::back

From cppreference.com
< cpp‎ | container‎ | vector
 
 
 
 
reference back();
(1) (constexpr since C++20)
const_reference back() const;
(2) (constexpr since C++20)

Returns a reference to the last element in the container.

Calling back on an empty container causes undefined behavior.

Contents

[edit] Parameters

(none)

[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

The following code uses back to display the last element of a std::vector<char>:

#include <vector>
#include <iostream>
 
int main()
{
    std::vector<char> letters{'a', 'b', 'c', 'd', 'e', 'f'};
 
    if (!letters.empty())
        std::cout << "The last character is '" << letters.back() << "'.\n";
}

Output:

The last character is 'f'.

[edit] See also

access the first element
(public member function) [edit]