list pop_back() function in C++ STL

The list::pop_back() is a built-in function in C++ STL which is used to remove an element from the back of a list container. That is, this function deletes the last element of a list container. This function thus decreases the size of the container by 1 as it deletes an element from the end of the list.

Syntax

list_name.pop_back();

Parameters

• The function does not accept any parameter.

Return Value

• This function does not return anything.

Example

The below program illustrates the list::pop_back() function in C++ STL.

C++

// CPP program to illustrate the
// list::pop_back() function
#include <bits/stdc++.h>
using namespace std;

int main()
{
    // Creating a list
    list<int> demoList;

    // Adding elements to the list
    // using push_back()
    demoList.push_back(10);
    demoList.push_back(20);
    demoList.push_back(30);
    demoList.push_back(40);

    // Initial List:
    cout << "Initial List: ";
    for (auto itr = demoList.begin(); itr != demoList.end();
         itr++)
        cout << *itr << " ";

    // removing an element from the end of List
    // using pop_back
    demoList.pop_back();

    // List after removing element from end
    cout << "\n\nList after removing an element from end: ";
    for (auto itr = demoList.begin(); itr != demoList.end();
         itr++)
        cout << *itr << " ";

    return 0;
}

Output

Initial List: 10 20 30 40 

List after removing an element from end: 10 20 30 

Time Complexity: O(1)
Auxiliary Space: O(1)