What Is Stack With Example in Data Structure?
A stack is a fundamental data structure in computer science that follows the Last-In-First-Out (LIFO) principle. It is an abstract data type with 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 from the stack.
To visualize a stack, imagine a stack of plates. You can only add or remove plates from the top of the stack.
The last plate you put on top is the first one you can remove. This concept applies to stacks in computer science as well.
Let’s consider an example to understand how a stack works in practice. Suppose we have an empty stack called ‘myStack’. We will perform some operations on this stack:
- Push: We push elements onto the stack using the push operation. Let’s push three elements onto ‘myStack’: 10, 20, and 30.
- myStack: [30, 20, 10]
- Pop: The pop operation removes the topmost element from the stack. If we perform a pop operation on ‘myStack’, it will remove 30.
- myStack: [20, 10]
- Push: Let’s push two more elements onto ‘myStack’: 40 and 50.
- myStack: [50, 40, 20, 10]
- Pop: If we perform a pop operation on ‘myStack’, it will remove 50.
- myStack: [40, 20, 10]
This example demonstrates how a stack behaves. The last element pushed onto the stack is always the first one to be removed.
Applications of Stacks
Stacks find diverse applications in computer science and software development. Some common examples include:
- Function Call Stack: When a function is called, its return address and local variables are stored on the stack. This allows the program to return to the calling function after execution.
- Expression Evaluation: Stacks are used to evaluate expressions in programming languages.
For example, when evaluating mathematical expressions like ‘(3 + 4) * 5’, a stack can be used to ensure proper order of operations.
- Undo/Redo Operations: Many applications use stacks to implement undo and redo functionality. Each action is pushed onto a stack so that it can be easily undone or redone.
In summary, a stack is an essential data structure that follows the Last-In-First-Out (LIFO) principle. It is widely used in computer science and software development for various applications.
Understanding stacks and their operations is crucial for every programmer.
With this understanding, you can now incorporate stacks into your programs to solve complex problems efficiently.