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Difference between revisions of "cpp/container/array/front"

From cppreference.com
< cpp‎ | container‎ | array
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Revision as of 19:28, 31 May 2013

 
 
 
 
reference front();
(1) (since C++11)
(constexpr since C++17)
const_reference front() const;
(2) (since C++11)
(constexpr since C++14)

Returns a reference to the first element in the container.

Calling front on an empty container causes undefined behavior.

Contents

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, 4>:

#include <cassert>
#include <array>
 
int main()
{
    std::array<char, 4> letters{'a', 'b', 'c', 'd'};
    assert(letters.front() == 'a');
}

See also

access the last element
(public member function) [edit]
returns a reverse iterator to the end
(public member function) [edit]
returns an iterator to the beginning
(public member function) [edit]
direct access to the underlying contiguous storage
(public member function) [edit]