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

NAME

std::list::front - std::list::front

Synopsis


reference front(); (1)
const_reference front() const; (2)


Returns a reference to the first element in the container.


Calling front on an empty container causes undefined behavior.

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::list<char>:

// Run this code


#include <list>
#include <iostream>


int main()
{
std::list<char> letters{'a', 'b', 'c', 'd', 'e', 'f'};


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

Output:


The first character is 'a'.

See also


back access the last element
(public member function)

2024.06.10 http://cppreference.com