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.
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