public member function
<list>

std::list::back

      reference back();
const_reference back() const;
Access last element
Returns a reference to the last element in the list container.

Unlike member list::end, which returns an iterator just past this element, this function returns a direct reference.

Calling this function on an empty container causes undefined behavior.

Parameters

none

Return value

A reference to the last element in the list.

If the list object is const-qualified, the function returns a const_reference. Otherwise, it returns a reference.

Member types reference and const_reference are the reference types to the elements of the list (see member types).

Example

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// list::back
#include <iostream>
#include <list>

int main ()
{
  std::list<int> mylist;

  mylist.push_back(10);

  while (mylist.back() != 0)
  {
    mylist.push_back ( mylist.back() -1 );
  }

  std::cout << "mylist contains:";
  for (std::list<int>::iterator it=mylist.begin(); it!=mylist.end() ; ++it)
    std::cout << ' ' << *it;

  std::cout << '\n';

  return 0;
}


Output:
mylist contains: 10 9 8 7 6 5 4 3 2 1 0

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed (neither the const nor the non-const versions modify the container).
The last element is potentially accessed or modified by the caller. Concurrently accessing or modifying other elements is safe.

Exception safety

If the container is not empty, the function never throws exceptions (no-throw guarantee).
Otherwise, it causes undefined behavior.

See also

  • 9281021542 2018-02-20
  • 632231541 2018-02-20
  • 9751491540 2018-02-20
  • 8333621539 2018-02-20
  • 995001538 2018-02-20
  • 6477441537 2018-02-20
  • 511981536 2018-02-19
  • 2072881535 2018-02-19
  • 6024461534 2018-02-19
  • 7594061533 2018-02-19
  • 9311341532 2018-02-19
  • 4928331531 2018-02-19
  • 38561530 2018-02-19
  • 7776611529 2018-02-19
  • 3038041528 2018-02-19
  • 9566341527 2018-02-19
  • 3936031526 2018-02-19
  • 9531111525 2018-02-19
  • 291211524 2018-02-19
  • 8962001523 2018-02-19