list crbegin() and crend() function in C++ STL

The list::crbegin() is a built-in function in c++ STL that returns a constant reverse iterator which points to the last element of the list i.e reversed beginning of container. The elements cannot be modified or changed as the iterator is a constant one.

Syntax:

list_name.crbegin()

Parameters: The function does not accept any parameters.

Return value: It returns a random access reverse iterator which points to the reverse beginning of the list.

Below program illustrates the above function:

// C++ program to illustrate the 
// list::crbegin() function 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    // declaration of the list 
    list<int> lis = { 10, 20, 30, 40, 50 }; 
  
    // prints the last element 
    cout << "The last element is: " << *lis.crbegin(); 
    cout << "\nList: "; 
  
    for (auto it = lis.crbegin(); it != lis.crend(); ++it) 
        cout << *it << " "; 
  
    return 0; 
} 

Output:

The last element is: 50
List: 50 40 30 20 10

The list::crend() is a built-in function in C++ STL that returns a constant reverse iterator which points to the theoretical element preceding the first element in the list i.e. the reverse end of the list. The elements cannot be modified or changed as the iterator is a constant one.

Syntax:

list_name.crend()

Parameters: The function does not accept any parameters.

Return value: It returns a constant random reverse iterator which points to the reverse end of the list.

Below program illustrates the above function:

// C++ program to illustrate the 
// list::crend() function 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    // declaration of the list 
    list<int> lis = { 7, 6, 5, 4, 3, 2 }; 
  
    cout << "List: " << endl; 
  
    for (auto it = lis.crbegin(); it != lis.crend(); ++it) 
        cout << *it << " "; 
  
    return 0; 
} 

Output:

List: 
2 3 4 5 6 7

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