C++ Vector crbegin

The crbegin function stands for reverse beginning. It is used to point the last character of the vector container.

crbegin vs rbegin

The crbegin function returns the constant reverse iterator while rbegin function returns the reverse iterator . The elemencpp tutorialed by the rbegin function can be modified but not by crbegin function.

Syntax

Consider a vector 'v'. Syntax would be:

const_reverse_iterator itr=v.crbegin();

Parameter

It does not contain any parameter.

Return value

It returns constant reverse iterator pointing to the reverse beginning of the container.

Example 1

Let's see a simple example.

#include <iostream>
#include<vector>
using namespace std;
int main()
{
vector<int> v{100,200,300,400};
vector<int>::const_reverse_iterator itr=v.crbegin();
  *itr=500;
cout<<*itr;
return 0;}

Output:

In this example, we are trying to modify the value using crbegin function which is not possible in this case.

Example 2

Let's see another simple example.

#include <iostream>
#include<vector>
using namespace std;
int main()
{
vector<string> v{"Mango","banana","strawberry","kiwi"};
vector<string>::const_reverse_iterator itr=v.crbegin();
cout<<*itr;
return 0;
}

Output:

In this example, crbegin function is used to access the last element of the vector container.

Example 3

Let's see a simple example.

#include <iostream>
#include<vector>
using namespace std;
int main()
{
vector<int> v{1,2,3,4,5};
vector<int>::const_reverse_iterator itr=v.crbegin()+2;
cout<<*itr;
return 0;
}

Output:

In this example, crbegin function is incremented by 2 to access the third element of the vector and this function access all the elements from backward.