Stack is a fundamental data structure in computer science that follows the Last-In-First-Out (LIFO) principle. It is widely used in various applications such as compiler implementations, recursion tracking, and undo operations. In this article, we will explore the different operations that can be performed on a stack and understand their significance in stack manipulation.
One of the essential operations in a stack is the push operation. This operation adds an element to the top of the stack. When an element is pushed onto the stack, it becomes the new top element, and all other elements shift one position down.
The element parameter represents the value to be added to the stack. The push operation increases the size of the stack by one.
The pop operation removes and returns the topmost element from the stack. It decreases the size of the stack by one and updates the top to point to the next element.
This operation does not require any parameters. It returns the value of the removed element or throws an error if called on an empty stack.
The peek, or top, operation allows us to access (without removing) the element at the top of a stack. It provides us with valuable information about what is currently at the top without altering its contents.
This operation does not modify or remove any elements from a stack. It simply returns the value of the top element, or throws an error if called on an empty stack.
The isEmpty operation checks whether the stack is empty or not. It returns true if there are no elements in the stack, and false otherwise.
This operation does not require any parameters. It can be used to determine whether additional operations can be performed on the stack.
The size operation returns the current number of elements in the stack. It is useful when we need to keep track of how many elements are stored in a particular stack.
This operation does not modify or remove any elements from a stack. It simply returns the number of elements present in the stack at a given time.
A stack data structure supports several operations, including push to add an element to the top, pop to remove and return the topmost element, peek to access the top element without removing it, isEmpty to check if there are any elements in the stack, and size to determine the number of elements currently stored. Understanding these operations is crucial for effectively working with stacks in various applications.