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list pop_front() function in C++ STL

The list::pop_front() is a built-in function in C++ STL which is used to remove an element from the front of a list container. This function thus decreases the size of the container by 1 as it deletes the element from the front of the list.

Syntax

list_name.pop_front();

Parameters

Return Value

Example

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




// CPP program to illustrate the
// list::pop_front() 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 front of List
    // using pop_front
    demoList.pop_front();
 
    // List after removing element from front
    cout << "\n\nList after removing an element from "
            "front: ";
    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 front: 20 30 40 

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

Article Tags :
C++