NAME

std::vector::back - std::vector::back

Synopsis

reference back(); (until C++20)
constexpr reference back(); (since C++20)
const_reference back() const; (until C++20)
constexpr const_reference back() const; (since C++20)

Returns a reference to the last element in the container.

Calling back on an empty container causes undefined behavior.

Parameters

(none)

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

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

// Run this code

#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'.