How to Check if a Deque is Empty in C++?

In C++, a deque is a container provided by the STL library that is similar to a queue. However, unlike queues, it allows insertion and deletion from both ends. In this article, we will learn how to determine whether a deque is empty or not in C++.

Example:

Input:
myDeque = {2, 4, 6 }

Output:
dq1 is not Empty.

Checking Whether a Deque is Empty in C++

To check if a std::deque is empty or not in C++, we can use the std::deque::empty() member function which returns a boolean value true if the deque is empty and false if the deque is not empty.

Syntax of std::deque::empty()

dq_name.empty()

C++ Program to Check if a Deque is Empty

The below program demonstrates how we can check if a deque is empty or not in C++.

Deque is not empty
After Removal: Deque is empty

Time Complexity: O(1)
Auxiliary Space: O(1)