NAME¶

std::vector::front - std::vector::front

Synopsis¶

reference front(); (1) (constexpr since C++20)
const_reference front() const; (2) (constexpr since C++20)

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::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 first character is '" << letters.front() << "'.\n";
}

Output:¶

The first character is 'a'.

See also¶

back access the last element
(public member function)