list front() function in C++ STL
The list::front() is a built-in function in C++ STL which is used to return a reference to the first element in a list container. Unlike the list::begin() function, this function returns a direct reference to the first element in the list container.
Syntax:
list_name.front()
Parameters: This function does not accept any parameter, it simply returns a reference to the first element in the list container.
Return Value: This function returns a direct reference to the first element in the list container.
Exception: This function creates an undefined behavior when used with an empty list container.
Below program illustrates the list::front() function.
// CPP program to illustrate the// list::front() function#include <bits/stdc++.h>using namespace std; int main(){ // Creating a list list<int> demoList; // Add elements to the List demoList.push_back(10); demoList.push_back(20); demoList.push_back(30); demoList.push_back(40); // get the first element using front() int ele = demoList.front(); // Print the first element cout << ele; return 0;} |
Output:
10
Note: This function works in constant time complexity.
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