Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://www.tutorialspoint.com/cpp_standard_library/cpp_deque_cbegin.htm below:

C++ Deque::cbegin() Function

The C++ std::deque::cbegin() function is used to return a constant iterator pointing to the first element, allowing the read-only access without modifying the container. This is useful for iterating through elements in a deque while ensuring they remain unchanged. It provides a way to access elements from the beginning of the deque in a safe and non-modifiable manner.

Following is the syntax for std::deque::cbegin() function.

const_iterator cbegin() const noexcept;

It does not accepts any parameters.

This function returns a const_iterator to the beginning of the sequence.

This function never throws exception.

The time complexity of this function is Constant i.e. O(1)

In the following example, we are going to consider the basic usage of cbegin() function.

#include <iostream>
#include <deque>
int main()
{
    std::deque<char> x = {'A', 'B', 'C', 'D'};
    auto a = x.cbegin();
    while (a != x.cend()) {
        std::cout << *a << " ";
        ++a;
    }
    return 0;
}

Output of the above code is as follows −

A B C D 

Consider the following example, where we are going to access the first element using cbegin() function

#include <iostream>
#include <deque>
int main()
{
    std::deque<std::string> a = {"TutorialsPoint", "Tutorix", "TP"};
    std::cout << " " << *a.cbegin() << std::endl;
    return 0;
}

Following is the output of the above code −

TutorialsPoint

In the following example, we are going to use the cbegin() function to get the constant iterator and compare the first element with the value.

#include <iostream>
#include <deque>
int main()
{
    std::deque<char> a = {'A', 'B', 'C', 'D'};
    auto x = a.cbegin();
    if (*x == 'A') {
        std::cout << "First Element is equal to given value." << std::endl;
    } else {
        std::cout << "First Element is not equal to given value." << std::endl;
    }
    return 0;
}

If we run the above code it will generate the following output −

First Element is equal to given value.

deque.htm

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4