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

See also


     access the last element
back (public member function)

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