C++ <list> - front() Function
The C++ list::front function returns a reference to the first element of the list. Please note that, Unlike the list::begin function, which returns the iterator pointing to the first element, it returns the a direct reference to the same element of the list.
Syntax
reference front(); const_reference front() const;
reference front(); const_reference front() const;
Parameters
No parameter is required.
Return Value
A reference to the first element of the list.
Time Complexity
Constant i.e, Θ(1)
Example:
In the example below, the list::front function is used to access the first element of the list called MyList.
#include <iostream> #include <list> using namespace std; int main (){ list<int> MyList{10, 20, 30, 40, 50}; cout<<"The first element of MyList is: "; cout<<MyList.front(); cout<<"\n\nAdd 100 to the first element of the MyList.\n"; MyList.front() = MyList.front() + 100; cout<<"Now, The first element of MyList is: "; cout<<MyList.front(); return 0; }
The output of the above code will be:
The first element of MyList is: 10 Add 100 to the first element of the MyList. Now, The first element of MyList is: 110
❮ C++ <list> Library