C++ Usage and examples of Deque cbegin()

C++ Deque (Double-ended Queue)

C ++ The cbegin() function of Deque returns a constant iterator that points to the first element of the deque container. This iterator can be incremented or decremented, just like the iterator returned by the begin() function. If the container is empty, the iterator returned will be equal to cend().

Syntax

const_iterator cbegin();

Parameters

It does not contain any parameters.

Return value

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

Example1

Let's look at a simple example

Example

#include <iostream>
#include<deque>
using namespace std;
int main()
{
　deque<string> fruit = {"mango", "apple", "banana", "kiwi"};
　deque<string>::const_iterator itr;
　itr = fruit.cbegin();
　　cout<<*itr;
　　return 0;
}

Output:

mango

In this example, the cbegin() function returns a constant iterator to the beginning of the container.

Example2

Let's look at a simple example

Example

#include <iostream>
#include<deque>
using namespace std;
int main()
{
　deque<int> k={100,200,300,400,500};
　deque<int>::const_iterator itr;
　itr=k.cbegin()+3;
　　cout<<*itr;
　　return 0;
}

Output:

400

In this example, the cbegin() function increments3. Therefore, it returns the4An iterator for each element.

C++ Deque (Double-ended Queue)