std::vector<T,Allocator>::front (3) - Linux Manuals

std::vector<T,Allocator>::front: std::vector<T,Allocator>::front

NAME

std::vector<T,Allocator>::front - std::vector<T,Allocator>::front

Synopsis

reference front();
const_reference front() const;

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::vector<char>:
// Run this code

  #include <vector>
  #include <iostream>

  int main()
  {
      std::vector<char> 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