C++ - C++ Deque Part 3: Accessing Elements in a Deque

Deques allow direct access to elements using:

.front(): Returns the first element.

.back(): Returns the last element.

.at(index): Returns the element at a specific index (with bounds checking).

Example 5: Accessing Front and Back Elements

#include <iostream>

#include <deque>

int main() {

    std::deque<char> letters = {'A', 'B', 'C', 'D', 'E'};

    std::cout << "First: " << letters.front() << std::endl;

    std::cout << "Last: " << letters.back() << std::endl;

    return 0;

}

Output:

mathematica

First: A

Last: E

Example 6: Using at() for Safe Index Access

#include <iostream>

#include <deque>

int main() {

    std::deque<int> dq = {1, 2, 3, 4, 5};

    std::cout << "Element at index 2: " << dq.at(2) << std::endl;

    return 0;

}

Output:

Element at index 2: 3