C++ - Array back() Function

The C++ array::back function is used to return a reference to the last element of the array. Please note that, Unlike the array::rbegin function, which returns the reverse iterator pointing to the last element, it returns the a direct reference to the same element of the array.

Syntax

• C++11

reference back();
const_reference back() const;

Parameters

No parameter is required.

Return Value

A reference to the last element of the array.

Time Complexity

Constant i.e, Θ(1).

Example:

In the below example, the array::back function is used to access the last element of the array MyArray.

#include <iostream>
#include <array>
using namespace std;
 
int main (){
  array<int, 5> MyArray{10, 20, 30, 40, 50};

  cout<<"The last element of MyArray is: ";
  cout<<MyArray.back();

  cout<<"\n\nAdd 100 to the last element of the MyArray.\n\n";
  MyArray.back() = MyArray.back() + 100;

  cout<<"Now, The last element of MyArray is: ";
  cout<<MyArray.back();  
  return 0;
}

The output of the above code will be:

The last element of MyArray is: 50

Add 100 to the last element of the MyArray.

Now, The last element of MyArray is: 150