What Is Enqueue Data Structure?


Heather Bennett

The enqueue data structure is a fundamental concept in computer science and plays a crucial role in many algorithms and applications. In this article, we will explore what an enqueue data structure is, how it works, and its various applications.

What is an Enqueue Data Structure?

An enqueue data structure, also known as a queue, is a linear data structure that follows the First-In-First-Out (FIFO) principle. It allows elements to be inserted at one end called the rear and removed from the other end called the front. In simpler terms, it resembles a real-life queue where people stand in line and are served one by one from the front.

Key Features of an Enqueue Data Structure:

  • Insertion: Elements are always inserted at the rear of the queue.
  • Deletion: Elements are always deleted from the front of the queue.
  • FIFO Principle: The element that gets added first will be the first one to be removed.

How Does an Enqueue Data Structure Work?

An enqueue data structure can be implemented using various programming constructs such as arrays or linked lists. Let’s consider a simple implementation using an array:

<pre><code>class Queue {
    constructor() {
        this.items = [];
    enqueue(element) {
    dequeue() {
        if (this.isEmpty()) {
            return "Underflow";
        return this.shift();
    isEmpty() {
        return this.length === 0;

In the above implementation, we define a class called Queue that represents the enqueue data structure. The items array holds the elements of the queue.

The enqueue() function adds an element to the rear of the queue, while the dequeue() function removes an element from the front of the queue. The isEmpty() function checks if the queue is empty or not.

Applications of Enqueue Data Structure

The enqueue data structure finds its utility in various real-world scenarios and algorithms:

1. Process Scheduling

In operating systems, queues are used to schedule processes based on their arrival time. The process that arrives first gets executed first.

2. Printer Spooler

A printer spooler uses a queue to manage multiple print jobs in order and ensures that each job is printed without any interference.

3. Breadth-First Search (BFS)

BFS algorithms use a queue to traverse a graph or tree level by level, exploring all adjacent nodes before moving on to deeper levels.

4. Web Server Request Handling

In web servers, requests are often handled using queues to ensure fairness and process them in the order they arrive.

The enqueue data structure is a versatile concept with numerous applications in computer science and beyond. Understanding its working and applications can greatly enhance your problem-solving skills and algorithmic thinking.