C++ Standard Library C++ STL Library

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

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