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std::array::front(3) C++ Standard Libary std::array::front(3)

NAME

std::array::front - std::array::front

Synopsis


reference front(); (until C++17)
constexpr reference front(); (since C++17)
const_reference front() const; (until C++14)
constexpr const_reference front() const; (since C++14)


Returns a reference to the first element in the container.


Calling front on an empty container is undefined.

Parameters


(none)

Return value


reference to the first element

Complexity


Constant

Notes


For a container c, the expression c.front() is equivalent to *c.begin().

Example


The following code uses front to display the first element of a std::array<char, 6>:

// Run this code


#include <array>
#include <iostream>


int main()
{
std::array<char, 6> letters {'o', 'm', 'g', 'w', 't', 'f'};


if (!letters.empty()) {
std::cout << "The first character is '" << letters.front() << "'.\n";
}
}

Output:


The first character is 'o'.

See also


back access the last element
(C++11) (public member function)

2022.07.31 http://cppreference.com