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vector::crend() function with example in C++ STL

C++ STL vector::crend() function: Here, we are going to learn about the crend() function of vector header in C++ STL with example.
Submitted by IncludeHelp, on May 11, 2019

C++ vector::crend() function

vector::crend() is a library function of "vector" header, it is used to get the first element of a vector from reverse ending, it returns a const reverse iterator pointing to the element preceding the first element (i.e. reverse ending) of a vector.

It returns a const_reverse_iterator which is an iterator point to the constant content(vector), the const_reverse_itertator can be increased or decreased just like an iterator but it cannot be used to update/modify the vector content it points to.

Note: To use vector, include <vector> header.

Syntax of vector::crend() function

    vector::crend();

Parameter(s): none – It accepts nothing.

Return value: const_reverse_iterator – It returns a const reverse iterator pointing to the element preceding the first elements of the vector.

Example:

    Input:
    vector<int> vector1{ 1, 2, 3, 4, 5 };

    Function call:
    vector<int>::const_iterator crit;
    crit = vector1.crend()-1;
    cout<<*crit;

    Output:
    1

C++ program to demonstrate example of vector::crend() function

//C++ STL program to demonstrate example of 
//vector::crend() function

#include <iostream>
#include <vector>
using namespace std;

int main()
{
    vector<int> v1;

    v1.push_back(10);
    v1.push_back(20);
    v1.push_back(30);
    v1.push_back(40);
    v1.push_back(50);

    //creating iterator
    vector<int>::const_reverse_iterator crit;
    crit = v1.crend()-1;
    cout << "first element is: " << *crit << endl;

    return 0;
}

Output

first element is: 10

Reference: C++ vector::crend()