std::array<T,N>::front (3) - Linux Manuals

std::array<T,N>::front: std::array<T,N>::front

NAME

std::array<T,N>::front - std::array<T,N>::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