list::push_front() method

Lists are sequence containers available in the C++ Standard Library. They allow non-contiguous memory allocation. List containers are implemented as doubly-linked lists. Compared to other sequence containers (eg: arrays, vectors etc.), lists have a better performance when it comes to inserting, moving or deleting elements. The list::push_front() is a method available in the STL which adds a new element at the beginning of the list container, before its current first element. It effectively increases the container size by one.

Syntax:

list_name.push_front(value);

Parameters: The list::push_front() method accepts a single parameter:
•Element to be inserted to the list
Return value: none

Example of list::push_front() method

#include <iostream>
#include <list>

using namespace std;

int main()
{
    list<int> L;
    L.push_front(10);
    L.push_front(20);
    L.push_front(30);
    L.push_front(40);

    cout<<"List contains:  \n";

    for( list<int>::iterator it = L.begin(); it != L.end(); ++it)
    {
        cout<<*it<<" <--> ";
    }
    cout<<"NULL";
}

Output:

List contains:
40 <--> 30 <--> 20 <--> 10 <--> NULL