list push_back() function in C++ STL

The list:push_back() function in C++ STL is used to add a new element to an existing list container. It takes the element to be added as a parameter and adds it to the list container.

Syntax

list_name.push_back(value)

Parameters

• This function accepts a single parameter which is a mandatory value. This refers to the elements needed to be added to the list, list_name.

Return Value

• The return type of this function is void and it does not return any value.

Example

The below program illustrates the list::push_back() function.

CPP

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

int main()
{
    // Initialization of list
    list<int> demo_list;

    // initial size of list
    cout << "Initial Size of the list: " << demo_list.size()
         << endl;

    // Adding elements to the list
    // using push_back function
    demo_list.push_back(10);
    demo_list.push_back(20);
    demo_list.push_back(30);

    // Size of list after adding
    // some elements
    cout << "Size of list after adding three "
         << "elements: " << demo_list.size();

    return 0;
}

Output

Initial Size of the list: 0
Size of list after adding three elements: 3

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