list empty() function in C++ STL

The list::empty() is a built-in function in C++ STL is used to check whether a particular list container is empty or not. This function does not modifies the list, it simply checks whether a list is empty or not, i.e. the size of list is zero or not.

Syntax:

list_name.empty() 

Parameters: This function does not accept any parameter, it simply checks whether a list container is empty or not.

Return Value: The return type of this function is boolean. It returns True is the size of the list container is zero otherwise it returns False.

Below program illustrates the list::empty() function.

filter_none

edit
close

play_arrow

link
brightness_4
code

// CPP program to illustrate the
// list::empty() function
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    // Creating a list
    list<int> demoList;
  
    // check if list is empty
    if (demoList.empty())
        cout << "Empty List\n";
    else
        cout << "Not Empty\n";
  
    // Add elements to the List
    demoList.push_back(10);
    demoList.push_back(20);
    demoList.push_back(30);
    demoList.push_back(40);
  
    // check again if list is empty
    if (demoList.empty())
        cout << "Empty List\n";
    else
        cout << "Not Empty\n";
  
    return 0;
}

chevron_right


Output:

Empty List
Not Empty

Note: This function works in constant time complexity.



My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.