What is a Simple Example of Stack? [2024]

Video: Introduction to Stacks.

Have you ever wondered what a stack is and how it works? In this article, we will dive deep into the world of stacks and explore a simple example to help you understand this fundamental data structure. So, let’s get started!

Quick Answer

A stack is a data structure that follows the Last-In-First-Out (LIFO) principle. It can be visualized as a stack of books, where the last book placed on top is the first one to be removed. Real-life examples of a stack include a deck of cards, piles of books, and piles of money.

Quick Tips and Facts

A stack is a collection of elements that supports two main operations: push and pop.
The push operation adds an element to the top of the stack, while the pop operation removes the topmost element.
The peek operation retrieves the topmost element without removing it.
Stacks can be implemented using arrays or linked lists.
Applications of stacks include expression evaluation, backtracking, function calls, parentheses checking, string reversal, syntax parsing, and memory management.

Background: Understanding Stacks

grey tower with round top under grey cloudy sky

Now that we have a quick overview, let’s delve deeper into the background and history of stacks. Understanding the concept behind stacks will help you grasp the simple example we’ll explore later.

A stack is a linear data structure that follows the LIFO (Last-In-First-Out) principle. It can be visualized as a stack of books, where the last book placed on top is the first one to be removed. The stack data structure is widely used in computer science and plays a crucial role in various algorithms and applications.

Stack Representation: A Simple Example

Video: Learn Stack data structures in 10 minutes .

To better understand stacks, let’s consider a simple example: a stack of plates. Imagine you’re at a buffet, and the plates are stacked on top of each other. When you want to take a plate, you always pick the one from the top. This is exactly how a stack works!

In this example, each plate represents an element in the stack. When you add a plate to the stack, it is placed on top of the existing plates. Similarly, when you remove a plate, you always take it from the top. This is the essence of the Last-In-First-Out principle.

Working of a Stack: Push and Pop Operations

Video: Operations Push and Pop | Stacks | Appliedcourse.

Now that we have a visual representation of a stack, let’s explore how it works. A stack supports two main operations: push and pop.

Push Operation: When you add a plate to the stack, it is called a push operation. The new plate is placed on top of the existing plates, becoming the topmost element of the stack.
Pop Operation: When you remove a plate from the stack, it is called a pop operation. The topmost plate is removed, revealing the plate that was placed before it.

Basic Operations on a Stack

Video: Stacks (Program 1) – Part 1.

In addition to push and pop, stacks support other basic operations that allow you to interact with the data structure. Let’s take a look at these operations:

Peek Operation: The peek operation retrieves the topmost element of the stack without removing it. It allows you to examine the element at the top without altering the stack’s structure.
isFull() Operation: This operation checks if the stack is full and cannot accommodate any more elements. It is particularly useful when implementing a stack using an array.
isEmpty() Operation: This operation checks if the stack is empty, meaning it does not contain any elements. It helps determine if the stack is ready to be populated or if it needs to be filled.

Implementation of a Stack

Video: Python Stacks – Python Tutorial for Absolute Beginners | Mosh.

Stacks can be implemented using arrays or linked lists. Let’s briefly explore both approaches:

Array Implementation: In this approach, an array is used to store the elements of the stack. The top of the stack is represented by an index that points to the last inserted element. When adding a new element, the index is incremented, and when removing an element, the index is decremented.
Linked List Implementation: In this approach, a linked list is used to represent the stack. Each node in the linked list contains an element and a reference to the next node. The top of the stack is represented by the head of the linked list.

Application of Stacks

Video: How to OVER Engineer a Website // What is a Tech Stack?

Stacks have a wide range of applications in computer science and beyond. Here are some common use cases:

Expression Evaluation: Stacks are used to evaluate arithmetic expressions, such as infix, postfix, and prefix notations.
Backtracking: Stacks are used in backtracking algorithms to keep track of the state and allow for efficient exploration of possible solutions.
Function Calls: Stacks are used to manage function calls in programming languages. Each function call is pushed onto the stack, and when a function returns, it is popped from the stack.
Parentheses Checking: Stacks are used to check the validity of parentheses in an expression. They ensure that opening and closing parentheses are balanced.
String Reversal: Stacks can be used to reverse a string by pushing each character onto the stack and then popping them in reverse order.
Syntax Parsing: Stacks are used in syntax parsing to validate the structure and correctness of a program or code snippet.
Memory Management: Stacks are used in memory management systems to allocate and deallocate memory efficiently.

FAQ

waterfalls painting

What is a stack in simple words?

In simple words, a stack is a data structure that follows the Last-In-First-Out (LIFO) principle. It can be visualized as a stack of objects, where the last object placed on top is the first one to be removed.

What is a stack for dummies?

A stack for dummies is a simplified explanation of the stack data structure that is easy to understand for beginners. It uses simple examples and analogies, such as a stack of books or a stack of plates, to illustrate the concept.

Which of the following is an example of a stack?

Examples of stacks include a deck of cards, piles of books, and piles of money. In these examples, the last item placed on top is the first one to be removed, following the Last-In-First-Out (LIFO) principle.

What is an example of a stack structure?

A stack structure can be represented by a stack of objects, where the last object placed on top is the first one to be removed. Real-life examples, such as a stack of plates or a stack of books, can help visualize the stack structure.

Conclusion

Matrix movie still

In conclusion, a stack is a fundamental data structure that follows the Last-In-First-Out (LIFO) principle. It can be visualized as a stack of objects, where the last object placed on top is the first one to be removed. We explored a simple example of a stack using a stack of plates, which helped us understand the basic operations and working of a stack. Stacks have various applications in computer science and play a crucial role in algorithms and data processing.

If you’re interested in learning more about data structures and their applications, check out our other articles on Stack Interface™. And remember, when it comes to understanding stacks, just think of a stack of plates!

Reference Links

Implementing Stacks in Data Structures – Simplilearn.com