C++ Standard Library C++ STL Library

C++ <list> - cbegin() Function



The C++ list::cbegin function returns the constant iterator (const_iterator) pointing to the first element of the list. Please note that, Unlike the list::front function, which returns a direct reference to the first element, it returns the const_iterator pointing to the same element of the list.

C++ cbegin cend

Note: A const_iterator is an iterator that points to constant value. The difference between iterator and const_iterator is that the const_iterator cannot be used to modify the content it points to, even if the list element is not itself constant.

Syntax

const_iterator cbegin() const noexcept;

Parameters

No parameter is required.

Return Value

A const_iterator to the beginning of the sequence container.

Time Complexity

Constant i.e, Θ(1).

Example:

In the example below, the list::cbegin function returns the const_iterator pointing to the first element of the list called MyList.

#include <iostream>
#include <list>
using namespace std;
 
int main (){
  list<string> MyList{"Alpha","Coding","Skills"};
  list<string>::const_iterator cit;

  cit = MyList.cbegin();
  cout<<*cit<<" ";
  cit++;
  cout<<*cit<<" ";
  cit++;
  cout<<*cit<<" ";
  return 0;
}

The output of the above code will be:

Alpha Coding Skills

Example:

Lets see another example where the list called MyList contains integer values and list::cbegin function is used with list::cend function to specify a range including all elements of the list container.

#include <iostream>
#include <list>
using namespace std;
 
int main (){
  list<int> MyList{10, 20, 30, 40, 50};
  list<int>::const_iterator cit;

  for(cit = MyList.cbegin(); cit != MyList.cend(); ++cit)
    cout<<*cit<<" ";

  return 0;
}

The output of the above code will be:

10 20 30 40 50 

❮ C++ <list> Library